From ff21c99b3c9c70ec5fefb8ac8bf3be87dcf64c0f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Tue, 11 Jul 2023 12:01:26 -0700
Subject: [PATCH 01/64] Impelement get_homogeneous_pages.

Unit tests forthcoming once we're directionally aligned.
---
 sqlakeyset/paging.py | 85 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index c1ed1d33..6850f883 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from functools import partial
+from dataclasses import dataclass
 from typing import (
     Any,
     List,
@@ -438,3 +439,87 @@ def get_page(
     place, backwards = process_args(after, before, page)
 
     return orm_get_page(query, per_page, place, backwards)
+
+
+# Do we need to support python 3.6?
+@dataclass
+class PageRequest(Generic[_TP]):
+    """See ``get_page()`` documentation for parameter explanations."""
+    query: Query[_TP]
+    per_page: int = PER_PAGE_DEFAULT
+    after: OptionalKeyset = None
+    before: OptionalKeyset = None
+    page: Optional[Union[MarkerLike, str]] = None
+    
+
+def get_homogeneous_page(queries: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]]:
+    """Get multiple pages of results for homogeneous legacy ORM queries.
+
+    This only involves a single round trip to the database. To do that, under the
+    hood it generates a UNION ALL. That means each query must select exactly the
+    same columns. They may have different filters or ordering, but must result in
+    selecting the same columns with the same names.
+
+    Resulting pages are returned in the same order as the original page requests.
+    """
+    if not queries:
+        return []
+
+    paging_queries = [_prepare_homogeneous_page(query, i) for i, query in enumerate(queries)]
+
+    query = paging_queries[0].query.query
+    query = query.union_all(*[q.query.query for q in paging_queries[1:]])
+
+    results = query.all()
+
+    # We need to make sure there's an entry for every page in case some return
+    # empty.
+    page_to_rows = {i: list() for i in range(len(queries))}
+    for row in results:
+        page_to_rows[row._page_identifier].append(row)
+
+    pages = []
+    for i in range(len(queries)):
+        rows = page_to_rows[i]
+        pages.append(paging_queries[i].page_from_rows(rows))
+
+
+@dataclass
+class _HomogeneousPagingQuery:
+    query: _PagingQuery
+    page_from_rows: Callable[[list[Row[_TP]]], Page[Row[_TP]]]
+
+
+def _prepare_homogeneous_page(
+        query: PageRequest[_TP], page_identifier: int
+) -> _HomogeneousPagingQuery:
+    """page_identifier MUST be a trusted int, as it is not escaped."""
+    # Should have no effect if called correctly, but let's be extra safe.
+    page_identifier = int(page_identifier)
+    place, backwards = process_args(query.after, query.before, query.page)
+
+    # Grab result_type and keys before adding the _page_identifier so that
+    # it isn't included in the results.
+    result_type = orm_result_type(query.query)
+    keys = orm_query_keys(query.query)
+    query.query = query.query.add_columns(
+        sa.sql.expression.literal_column(str(page_identifier)).label("_page_identifier")
+    )
+
+    # Could we order by page identifier to do the page collation in the DB?
+
+    paging_query = prepare_paging(
+        q=query.query,
+        per_page=query.per_page,
+        place=place,
+        backwards=backwards,
+        orm=True,
+        dialect=query.query.session.get_bind().dialect,
+    )
+
+    def page_from_rows(rows):
+        return orm_page_from_rows(
+            paging_query, rows, keys, result_type, per_page, backwards, current_place=place
+        )
+
+    return _HomogeneousPagingQuery(query=paging_query, page_from_rows=page_from_rows)

From eff5d52b7a5c36477c7a9cda30a9776371757d7d Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 08:30:38 -0700
Subject: [PATCH 02/64] Check in unit test for multi-page lookup.

---
 sqlakeyset/paging.py |  47 +++++++++---------
 tests/test_paging.py | 111 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 112 insertions(+), 46 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 6850f883..5b38e3e2 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -22,7 +22,7 @@
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
 from sqlalchemy.orm.query import Query
-from sqlalchemy.sql.expression import ColumnElement
+from sqlalchemy.sql.expression import ColumnElement, literal_column
 from sqlalchemy.sql.selectable import Select
 
 from .columns import OC, MappedOrderColumn, find_order_key, parse_ob_clause
@@ -441,7 +441,6 @@ def get_page(
     return orm_get_page(query, per_page, place, backwards)
 
 
-# Do we need to support python 3.6?
 @dataclass
 class PageRequest(Generic[_TP]):
     """See ``get_page()`` documentation for parameter explanations."""
@@ -452,7 +451,7 @@ class PageRequest(Generic[_TP]):
     page: Optional[Union[MarkerLike, str]] = None
     
 
-def get_homogeneous_page(queries: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]]:
+def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]]:
     """Get multiple pages of results for homogeneous legacy ORM queries.
 
     This only involves a single round trip to the database. To do that, under the
@@ -462,59 +461,61 @@ def get_homogeneous_page(queries: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]
 
     Resulting pages are returned in the same order as the original page requests.
     """
-    if not queries:
+    if not requests:
         return []
 
-    paging_queries = [_prepare_homogeneous_page(query, i) for i, query in enumerate(queries)]
+    prepared_queries = [_prepare_homogeneous_page(request, i) for i, query in enumerate(requests)]
 
-    query = paging_queries[0].query.query
-    query = query.union_all(*[q.query.query for q in paging_queries[1:]])
+    query = prepared_queries[0].paging_query.query
+    query = query.union_all(*[p.prepared_query.query for p in prepared_queries[1:]])
 
     results = query.all()
 
     # We need to make sure there's an entry for every page in case some return
     # empty.
-    page_to_rows = {i: list() for i in range(len(queries))}
+    page_to_rows = {i: list() for i in range(len(requests))}
     for row in results:
         page_to_rows[row._page_identifier].append(row)
 
     pages = []
-    for i in range(len(queries)):
+    for i in range(len(requests)):
         rows = page_to_rows[i]
-        pages.append(paging_queries[i].page_from_rows(rows))
+        pages.append(prepared_queries[i].page_from_rows(rows))
+    return pages
 
 
 @dataclass
-class _HomogeneousPagingQuery:
-    query: _PagingQuery
+class _PreparedQuery:
+    paging_query: _PagingQuery
     page_from_rows: Callable[[list[Row[_TP]]], Page[Row[_TP]]]
 
 
 def _prepare_homogeneous_page(
-        query: PageRequest[_TP], page_identifier: int
-) -> _HomogeneousPagingQuery:
+        request: PageRequest[_TP], page_identifier: int
+) -> _PreparedQuery:
     """page_identifier MUST be a trusted int, as it is not escaped."""
     # Should have no effect if called correctly, but let's be extra safe.
     page_identifier = int(page_identifier)
-    place, backwards = process_args(query.after, query.before, query.page)
+    place, backwards = process_args(request.after, request.before, request.page)
 
     # Grab result_type and keys before adding the _page_identifier so that
     # it isn't included in the results.
-    result_type = orm_result_type(query.query)
-    keys = orm_query_keys(query.query)
-    query.query = query.query.add_columns(
-        sa.sql.expression.literal_column(str(page_identifier)).label("_page_identifier")
+    query = request.query
+    result_type = orm_result_type(query)
+    keys = orm_query_keys(query)
+    query = query.add_columns(
+        literal_column(str(page_identifier)).label("_page_identifier")
     )
 
     # Could we order by page identifier to do the page collation in the DB?
 
     paging_query = prepare_paging(
-        q=query.query,
-        per_page=query.per_page,
+        q=query,
+        per_page=request.per_page,
         place=place,
         backwards=backwards,
         orm=True,
-        dialect=query.query.session.get_bind().dialect,
+        dialect=query.session.get_bind().dialect,
     )
 
     def page_from_rows(rows):
@@ -522,4 +523,4 @@ def page_from_rows(rows):
             paging_query, rows, keys, result_type, per_page, backwards, current_place=place
         )
 
-    return _HomogeneousPagingQuery(query=paging_query, page_from_rows=page_from_rows)
+    return _PreparedQuery(paging_query=paging_query, page_from_rows=page_from_rows)
diff --git a/tests/test_paging.py b/tests/test_paging.py
index 721224f5..f21dd350 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -14,10 +14,11 @@
 valid sqlalchemy versions are 1.3.0, 1.4.0, 2.0.0.)"""
 import warnings
 from packaging import version
+from typing import Any
 
 import pytest
 import sqlalchemy
-from sqlalchemy.orm import sessionmaker, aliased, Bundle
+from sqlalchemy.orm import sessionmaker, aliased, Bundle, Query
 from sqlalchemy import (
     desc,
     func,
@@ -25,12 +26,16 @@
 
 from sqlakeyset import (
     get_page,
+    get_homogeneous_pages,
     select_page,
     serialize_bookmark,
     unserialize_bookmark,
     InvalidPage,
+    PageRequest,
 )
 from sqlakeyset.paging import process_args
+from sqlakeyset.results import Page
+from sqlakeyset.types import MarkerLike
 from conftest import (
     Book,
     Author,
@@ -49,6 +54,76 @@
 warnings.simplefilter("error")
 
 
+@dataclass
+class _PageTracker:
+    query: Query
+    unpaged: list
+    gathered: list
+    backwards: bool
+    page: tuple[MarkerLike | str, bool]
+    page_with_paging: Page | None = None
+
+
+def assert_paging_orm(page_with_paging, gathered, backwards, unpaged):
+    """Returns the next page, or None if no further pages."""
+    paging = page_with_paging.paging
+
+    assert paging.current == page
+
+    if backwards:
+        gathered = page_with_paging + gathered
+    else:
+        gathered = gathered + page_with_paging
+
+    if len(gathered) < len(unpaged):
+        # Ensure each page is the correct size
+        assert paging.has_further
+        assert len(page_with_paging) == per_page
+    else:
+        assert not paging.has_further
+
+    if not page_with_paging:
+        assert not paging.has_further
+        assert paging.further == paging.current
+        assert paging.current_opposite == (None, not paging.backwards)
+        # Is this return None necessary or will paging.further just be None?
+        return None
+
+    return paging.further
+
+
+def check_multiple_paging_orm(qs):
+    page_trackers = [
+        _PageTracker(
+            query=q,
+            gathered=[],
+            backwards=(i % 2 == 0),
+            page=(None, i % 2 == 0),
+            unpaged=q.all(),
+        )
+        for q in qs
+    ]
+    while True:
+        for t in page_tackers:
+            t.page = unserialize_bookmark(serialize_bookmark(t.page))
+
+        page_requests = [
+            PageRequest(query=t.query, per_page=i, page=t.page) for i, t in enumerate(page_trackers)
+        ]
+        pages_with_paging = get_homogeneous_pages(page_requests)
+        for p, t in zip(pages_with_paging, page_trackers):
+            page_trackers.page_with_paging = p
+
+        for t in list(page_tackers):
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged)
+            if page is None:
+                # Ensure union of pages is original q.all()
+                assert t.gathered == t.unpaged
+                page_trackers.remove(t)
+
+            t.page = page
+
+
 def check_paging_orm(q):
     item_counts = range(1, 12)
 
@@ -65,28 +140,8 @@ def check_paging_orm(q):
                 page = unserialize_bookmark(serialized_page)
 
                 page_with_paging = get_page(q, per_page=per_page, page=serialized_page)
-                paging = page_with_paging.paging
-
-                assert paging.current == page
-
-                if backwards:
-                    gathered = page_with_paging + gathered
-                else:
-                    gathered = gathered + page_with_paging
-
-                page = paging.further
-
-                if len(gathered) < len(unpaged):
-                    # Ensure each page is the correct size
-                    assert paging.has_further
-                    assert len(page_with_paging) == per_page
-                else:
-                    assert not paging.has_further
-
-                if not page_with_paging:
-                    assert not paging.has_further
-                    assert paging.further == paging.current
-                    assert paging.current_opposite == (None, not paging.backwards)
+                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged)
+                if page is None:
                     break
 
             # Ensure union of pages is original q.all()
@@ -361,6 +416,16 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
         check_paging_orm(q=q)
 
 
+def test_orm_multiple_pages(dburl):
+    with S(dburl, echo=ECHO) as s:
+        qs = [
+            s.query(Animal).order_by(Animal.leg_count, Animal.id),
+            s.query(Animal).filter(Animal.leg_count == 4).order_by(Animal.id),
+            s.query(Animal).order_by(Animal.leg_count, Animal.id.desc()),
+        ]
+    check_multiple_paging_orm(qs=qs)
+
+
 def test_core(dburl):
     selectable = (
         select(Book.b, Book.d, Book.id, Book.c)

From d37132bdc8ddc2e51d4d47cc44b9c52eed3e5da2 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 08:34:44 -0700
Subject: [PATCH 03/64] Fix missing symbols.

---
 sqlakeyset/paging.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 5b38e3e2..14f71ba2 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -6,6 +6,8 @@
 from dataclasses import dataclass
 from typing import (
     Any,
+    Callable,
+    Generic,
     List,
     NamedTuple,
     Optional,
@@ -449,7 +451,7 @@ class PageRequest(Generic[_TP]):
     after: OptionalKeyset = None
     before: OptionalKeyset = None
     page: Optional[Union[MarkerLike, str]] = None
-    
+
 
 def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]]:
     """Get multiple pages of results for homogeneous legacy ORM queries.
@@ -464,7 +466,7 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     if not requests:
         return []
 
-    prepared_queries = [_prepare_homogeneous_page(request, i) for i, query in enumerate(requests)]
+    prepared_queries = [_prepare_homogeneous_page(request, i) for i, request in enumerate(requests)]
 
     query = prepared_queries[0].paging_query.query
     query = query.union_all(*[p.prepared_query.query for p in prepared_queries[1:]])
@@ -520,7 +522,7 @@ def _prepare_homogeneous_page(
 
     def page_from_rows(rows):
         return orm_page_from_rows(
-            paging_query, rows, keys, result_type, per_page, backwards, current_place=place
+            paging_query, rows, keys, result_type, request.per_page, backwards, current_place=place
         )
 
     return _PreparedQuery(paging_query=paging_query, page_from_rows=page_from_rows)

From df7466cdb3019526af8d7f48990118a1183d7353 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 09:39:22 -0700
Subject: [PATCH 04/64] Fix flake8 test_paging.py

---
 tests/test_paging.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index f21dd350..b6295586 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -13,8 +13,8 @@
 docker containers. (Available python versions are 3.7, 3.8, 3.9, 3.10, 3.11 and
 valid sqlalchemy versions are 1.3.0, 1.4.0, 2.0.0.)"""
 import warnings
+from dataclasses import dataclass
 from packaging import version
-from typing import Any
 
 import pytest
 import sqlalchemy
@@ -64,11 +64,11 @@ class _PageTracker:
     page_with_paging: Page | None = None
 
 
-def assert_paging_orm(page_with_paging, gathered, backwards, unpaged):
+def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, per_page):
     """Returns the next page, or None if no further pages."""
     paging = page_with_paging.paging
 
-    assert paging.current == page
+    assert paging.current == page_with_paging.page
 
     if backwards:
         gathered = page_with_paging + gathered
@@ -101,10 +101,10 @@ def check_multiple_paging_orm(qs):
             page=(None, i % 2 == 0),
             unpaged=q.all(),
         )
-        for q in qs
+        for i, q in enumerate(qs)
     ]
     while True:
-        for t in page_tackers:
+        for t in page_trackers:
             t.page = unserialize_bookmark(serialize_bookmark(t.page))
 
         page_requests = [
@@ -114,8 +114,8 @@ def check_multiple_paging_orm(qs):
         for p, t in zip(pages_with_paging, page_trackers):
             page_trackers.page_with_paging = p
 
-        for t in list(page_tackers):
-            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged)
+        for i, t in enumerate(list(page_trackers)):
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, i)
             if page is None:
                 # Ensure union of pages is original q.all()
                 assert t.gathered == t.unpaged
@@ -140,7 +140,7 @@ def check_paging_orm(q):
                 page = unserialize_bookmark(serialized_page)
 
                 page_with_paging = get_page(q, per_page=per_page, page=serialized_page)
-                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged)
+                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged, per_page)
                 if page is None:
                     break
 

From 4843e68e8e623f594758d6c279ee344c84f05db8 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:05:35 -0700
Subject: [PATCH 05/64] Export get_homogeneous_pages.

---
 sqlakeyset/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sqlakeyset/__init__.py b/sqlakeyset/__init__.py
index 322327c0..7d054cf2 100644
--- a/sqlakeyset/__init__.py
+++ b/sqlakeyset/__init__.py
@@ -16,6 +16,7 @@
 
 __all__ = [
     "get_page",
+    "get_homogeneous_pages",
     "select_page",
     "serialize_bookmark",
     "unserialize_bookmark",

From 9985e4ed6423cdf18573c095cd4c91665b90d277 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:11:52 -0700
Subject: [PATCH 06/64] Actually import get_homogeneous_pages.

---
 sqlakeyset/__init__.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sqlakeyset/__init__.py b/sqlakeyset/__init__.py
index 7d054cf2..63f55a6d 100644
--- a/sqlakeyset/__init__.py
+++ b/sqlakeyset/__init__.py
@@ -1,4 +1,4 @@
-from .paging import get_page, select_page, InvalidPage
+from .paging import get_homogeneous_pages, get_page, select_page, InvalidPage
 from .results import (
     Page,
     Paging,
@@ -15,8 +15,8 @@
 from .types import Keyset, Marker
 
 __all__ = [
-    "get_page",
     "get_homogeneous_pages",
+    "get_page",
     "select_page",
     "serialize_bookmark",
     "unserialize_bookmark",

From bd486e10a823f06b5a428b3f774cf5d9e29e8d81 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:14:05 -0700
Subject: [PATCH 07/64] Add PageRequest.

---
 sqlakeyset/__init__.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/__init__.py b/sqlakeyset/__init__.py
index 63f55a6d..6b286d8d 100644
--- a/sqlakeyset/__init__.py
+++ b/sqlakeyset/__init__.py
@@ -1,4 +1,4 @@
-from .paging import get_homogeneous_pages, get_page, select_page, InvalidPage
+from .paging import get_homogeneous_pages, get_page, select_page, InvalidPage, PageRequest
 from .results import (
     Page,
     Paging,
@@ -21,6 +21,7 @@
     "serialize_bookmark",
     "unserialize_bookmark",
     "Page",
+    "PageRequest",
     "Paging",
     "Keyset",
     "Marker",

From e53424376c6cecf00fb333c51f78b39ab0975583 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:17:32 -0700
Subject: [PATCH 08/64] Fix bad symbol.

---
 tests/test_paging.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index b6295586..6230042c 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -64,11 +64,11 @@ class _PageTracker:
     page_with_paging: Page | None = None
 
 
-def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, per_page):
+def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page):
     """Returns the next page, or None if no further pages."""
     paging = page_with_paging.paging
 
-    assert paging.current == page_with_paging.page
+    assert paging.current == page
 
     if backwards:
         gathered = page_with_paging + gathered
@@ -115,7 +115,7 @@ def check_multiple_paging_orm(qs):
             page_trackers.page_with_paging = p
 
         for i, t in enumerate(list(page_trackers)):
-            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, i)
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i)
             if page is None:
                 # Ensure union of pages is original q.all()
                 assert t.gathered == t.unpaged
@@ -140,7 +140,7 @@ def check_paging_orm(q):
                 page = unserialize_bookmark(serialized_page)
 
                 page_with_paging = get_page(q, per_page=per_page, page=serialized_page)
-                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged, per_page)
+                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page)
                 if page is None:
                     break
 

From 5e6fd6a34d55c5144a89fd812e690cff49e8bec6 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:22:09 -0700
Subject: [PATCH 09/64] Extend gathered.

---
 tests/test_paging.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 6230042c..9ecf0bf0 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -65,15 +65,18 @@ class _PageTracker:
 
 
 def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page):
-    """Returns the next page, or None if no further pages."""
+    """Returns the next page, or None if no further pages.
+
+    Modifies gathered in place.
+    """
     paging = page_with_paging.paging
 
     assert paging.current == page
 
     if backwards:
-        gathered = page_with_paging + gathered
+        gathered[:0] = page_with_paging + gathered
     else:
-        gathered = gathered + page_with_paging
+        gathered.extend(page_with_paging)
 
     if len(gathered) < len(unpaged):
         # Ensure each page is the correct size

From f5075c3418bb3c6f26d70d0304e55799224ea21a Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:24:55 -0700
Subject: [PATCH 10/64] Use Union instead of |.

---
 tests/test_paging.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 9ecf0bf0..f3495010 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -15,6 +15,7 @@
 import warnings
 from dataclasses import dataclass
 from packaging import version
+from typing import Union
 
 import pytest
 import sqlalchemy
@@ -60,7 +61,7 @@ class _PageTracker:
     unpaged: list
     gathered: list
     backwards: bool
-    page: tuple[MarkerLike | str, bool]
+    page: tuple[Union[MarkerLike, str], bool]
     page_with_paging: Page | None = None
 
 
@@ -74,7 +75,7 @@ def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_
     assert paging.current == page
 
     if backwards:
-        gathered[:0] = page_with_paging + gathered
+        gathered[:0] = page_with_paging
     else:
         gathered.extend(page_with_paging)
 

From 9aae97fcc14503a8832e82fa0e07a22da98cf4ba Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:26:41 -0700
Subject: [PATCH 11/64] Use Tuple instead of tuple.

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index f3495010..9aebd226 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -15,7 +15,7 @@
 import warnings
 from dataclasses import dataclass
 from packaging import version
-from typing import Union
+from typing import Tuple, Union
 
 import pytest
 import sqlalchemy
@@ -61,7 +61,7 @@ class _PageTracker:
     unpaged: list
     gathered: list
     backwards: bool
-    page: tuple[Union[MarkerLike, str], bool]
+    page: Tuple[Union[MarkerLike, str], bool]
     page_with_paging: Page | None = None
 
 

From cbefa301e09ada21dd97516f7ed50b1c9b4b6c76 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:31:45 -0700
Subject: [PATCH 12/64] Use Book instead of Animal.

---
 tests/test_paging.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 9aebd226..4fad4629 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -423,9 +423,9 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
 def test_orm_multiple_pages(dburl):
     with S(dburl, echo=ECHO) as s:
         qs = [
-            s.query(Animal).order_by(Animal.leg_count, Animal.id),
-            s.query(Animal).filter(Animal.leg_count == 4).order_by(Animal.id),
-            s.query(Animal).order_by(Animal.leg_count, Animal.id.desc()),
+            s.query(Book).order_by(Book.author_id, Book.id),
+            s.query(Book).filter(Book.author_id < 4).order_by(Book.id),
+            s.query(Book).order_by(Book.author_id, Book.id.desc()),
         ]
     check_multiple_paging_orm(qs=qs)
 

From bb86b7e5c85567890ca7f1e734a8b40263e84a7b Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:34:20 -0700
Subject: [PATCH 13/64] More python 3.7 and fix wrong symbol name.

---
 sqlakeyset/paging.py | 2 +-
 tests/test_paging.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 14f71ba2..952f407b 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -469,7 +469,7 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     prepared_queries = [_prepare_homogeneous_page(request, i) for i, request in enumerate(requests)]
 
     query = prepared_queries[0].paging_query.query
-    query = query.union_all(*[p.prepared_query.query for p in prepared_queries[1:]])
+    query = query.union_all(*[p.paging_query.query for p in prepared_queries[1:]])
 
     results = query.all()
 
diff --git a/tests/test_paging.py b/tests/test_paging.py
index 4fad4629..6399f46c 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -15,7 +15,7 @@
 import warnings
 from dataclasses import dataclass
 from packaging import version
-from typing import Tuple, Union
+from typing import Optional, Tuple, Union
 
 import pytest
 import sqlalchemy
@@ -62,7 +62,7 @@ class _PageTracker:
     gathered: list
     backwards: bool
     page: Tuple[Union[MarkerLike, str], bool]
-    page_with_paging: Page | None = None
+    page_with_paging: Optional[Page] = None
 
 
 def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page):

From cdd0fc23c4231b904492432d8eec82d6a651232b Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:38:20 -0700
Subject: [PATCH 14/64] Improve tests.

---
 tests/test_paging.py | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 6399f46c..350fff95 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -424,10 +424,23 @@ def test_orm_multiple_pages(dburl):
     with S(dburl, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.author_id, Book.id),
-            s.query(Book).filter(Book.author_id < 4).order_by(Book.id),
+            s.query(Book).filter(Book.author_id == 1).order_by(Book.id),
             s.query(Book).order_by(Book.author_id, Book.id.desc()),
         ]
-    check_multiple_paging_orm(qs=qs)
+        check_multiple_paging_orm(qs=qs)
+
+
+def test_orm_multiple_pages_one_query(dburl):
+    with S(dburl, echo=ECHO) as s:
+        qs = [
+            s.query(Book).order_by(Book.id),
+        ]
+        check_multiple_paging_orm(qs=qs)
+
+
+def test_orm_multiple_pages_empty_queries(dburl):
+    with S(dburl, echo=ECHO) as s:
+        assert get_homogeneous_pages([]) == []
 
 
 def test_core(dburl):

From 2af1ca2a6181e446c5bfe5e4c37b12d250476eb1 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:40:45 -0700
Subject: [PATCH 15/64] Remove unused db session.

---
 tests/test_paging.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 350fff95..f68991ff 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -439,8 +439,7 @@ def test_orm_multiple_pages_one_query(dburl):
 
 
 def test_orm_multiple_pages_empty_queries(dburl):
-    with S(dburl, echo=ECHO) as s:
-        assert get_homogeneous_pages([]) == []
+    assert get_homogeneous_pages([]) == []
 
 
 def test_core(dburl):

From 76c2939d9312ec4498741c52ccd5ac0a3bd2823e Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:52:36 -0700
Subject: [PATCH 16/64] Exclude sqlite.

---
 sqlakeyset/paging.py | 3 +++
 tests/conftest.py    | 1 +
 tests/test_paging.py | 6 +++---
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 952f407b..eb158cb7 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -461,6 +461,9 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     same columns. They may have different filters or ordering, but must result in
     selecting the same columns with the same names.
 
+    Note: This requires the underlying database to support ORDER BY and LIMIT
+    statements in components of a compound select, which SQLite does not.
+
     Resulting pages are returned in the same order as the original page requests.
     """
     if not requests:
diff --git a/tests/conftest.py b/tests/conftest.py
index 37421080..4d264386 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -246,6 +246,7 @@ def _dburl(request):
 
 dburl = pytest.fixture(params=SUPPORTED_ENGINES)(_dburl)
 no_mysql_dburl = pytest.fixture(params=["sqlite", "postgresql"])(_dburl)
+no_sqlite_dburl = pytest.fixture(params=["mysql", "postgresql"])(_dburl)
 pg_only_dburl = pytest.fixture(params=["postgresql"])(_dburl)
 
 
diff --git a/tests/test_paging.py b/tests/test_paging.py
index f68991ff..8da4e5e6 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -420,7 +420,7 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
         check_paging_orm(q=q)
 
 
-def test_orm_multiple_pages(dburl):
+def test_orm_multiple_pages(no_sqlite_url):
     with S(dburl, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.author_id, Book.id),
@@ -430,7 +430,7 @@ def test_orm_multiple_pages(dburl):
         check_multiple_paging_orm(qs=qs)
 
 
-def test_orm_multiple_pages_one_query(dburl):
+def test_orm_multiple_pages_one_query(no_sqlite_url):
     with S(dburl, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.id),
@@ -438,7 +438,7 @@ def test_orm_multiple_pages_one_query(dburl):
         check_multiple_paging_orm(qs=qs)
 
 
-def test_orm_multiple_pages_empty_queries(dburl):
+def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
 

From 6867d838d8b9311b9a47a63873377e6552137c9e Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:54:52 -0700
Subject: [PATCH 17/64] s/dburl/no_sqlite_url

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 8da4e5e6..0764cbcd 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -421,7 +421,7 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
 
 
 def test_orm_multiple_pages(no_sqlite_url):
-    with S(dburl, echo=ECHO) as s:
+    with S(no_sqlite_url, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.author_id, Book.id),
             s.query(Book).filter(Book.author_id == 1).order_by(Book.id),
@@ -431,7 +431,7 @@ def test_orm_multiple_pages(no_sqlite_url):
 
 
 def test_orm_multiple_pages_one_query(no_sqlite_url):
-    with S(dburl, echo=ECHO) as s:
+    with S(no_sqlite_url, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.id),
         ]

From 19ff0099048f5cf066d3c87e47bbd99efd54f4b7 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 15:57:43 -0700
Subject: [PATCH 18/64] s/url/dburl

---
 tests/test_paging.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 0764cbcd..5432c95a 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -420,8 +420,8 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
         check_paging_orm(q=q)
 
 
-def test_orm_multiple_pages(no_sqlite_url):
-    with S(no_sqlite_url, echo=ECHO) as s:
+def test_orm_multiple_pages(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.author_id, Book.id),
             s.query(Book).filter(Book.author_id == 1).order_by(Book.id),
@@ -430,8 +430,8 @@ def test_orm_multiple_pages(no_sqlite_url):
         check_multiple_paging_orm(qs=qs)
 
 
-def test_orm_multiple_pages_one_query(no_sqlite_url):
-    with S(no_sqlite_url, echo=ECHO) as s:
+def test_orm_multiple_pages_one_query(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
             s.query(Book).order_by(Book.id),
         ]

From abdef8af139c050d8d7212b63a800878edcb6029 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Thu, 13 Jul 2023 16:01:12 -0700
Subject: [PATCH 19/64] Fix for loop variable.

---
 tests/test_paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 5432c95a..6bb80f8f 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -116,7 +116,7 @@ def check_multiple_paging_orm(qs):
         ]
         pages_with_paging = get_homogeneous_pages(page_requests)
         for p, t in zip(pages_with_paging, page_trackers):
-            page_trackers.page_with_paging = p
+            t.page_with_paging = p
 
         for i, t in enumerate(list(page_trackers)):
             page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i)

From a5514cfd8195fcd6eb2ef03c44e1256fcdf4f13e Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 06:32:33 -0700
Subject: [PATCH 20/64] Per page should be at least 1.

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 6bb80f8f..ef582e4e 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -112,14 +112,14 @@ def check_multiple_paging_orm(qs):
             t.page = unserialize_bookmark(serialize_bookmark(t.page))
 
         page_requests = [
-            PageRequest(query=t.query, per_page=i, page=t.page) for i, t in enumerate(page_trackers)
+            PageRequest(query=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
         ]
         pages_with_paging = get_homogeneous_pages(page_requests)
         for p, t in zip(pages_with_paging, page_trackers):
             t.page_with_paging = p
 
         for i, t in enumerate(list(page_trackers)):
-            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i)
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 1)
             if page is None:
                 # Ensure union of pages is original q.all()
                 assert t.gathered == t.unpaged

From b7a34f5d764cc7ada3d2c78393baf012dc76c4be Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 06:57:09 -0700
Subject: [PATCH 21/64] Fix UNION ALL ordering which isn't guaranteed.

---
 sqlakeyset/paging.py | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index eb158cb7..6a4481c0 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -19,7 +19,7 @@
 )
 from typing_extensions import Literal  # to keep python 3.7 support
 
-from sqlalchemy import tuple_, and_, or_
+from sqlalchemy import tuple_, and_, or_, func, text
 from sqlalchemy.engine import Connection
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
@@ -472,8 +472,9 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     prepared_queries = [_prepare_homogeneous_page(request, i) for i, request in enumerate(requests)]
 
     query = prepared_queries[0].paging_query.query
-    query = query.union_all(*[p.paging_query.query for p in prepared_queries[1:]])
+    query = query.union_all(*[p.paging_query.query for p in prepared_queries[1:]]).order_by(text("_page_identifier"), text("_row_number"))
 
+    print(query)
     results = query.all()
 
     # We need to make sure there's an entry for every page in case some return
@@ -508,9 +509,6 @@ def _prepare_homogeneous_page(
     query = request.query
     result_type = orm_result_type(query)
     keys = orm_query_keys(query)
-    query = query.add_columns(
-        literal_column(str(page_identifier)).label("_page_identifier")
-    )
 
     # Could we order by page identifier to do the page collation in the DB?
 
@@ -522,6 +520,13 @@ def _prepare_homogeneous_page(
         orm=True,
         dialect=query.session.get_bind().dialect,
     )
+    query = paging_query.query
+    paging_query.query = paging_query.query.add_columns(
+        literal_column(str(page_identifier)).label("_page_identifier"),
+        func.ROW_NUMBER().over(
+            order_by=[c.element for c in paging_query.order_columns]
+        ).label("_row_number")
+    )
 
     def page_from_rows(rows):
         return orm_page_from_rows(

From 2f4f4bd92bacac07a1dc82c08728d428dbf3fa3f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:02:28 -0700
Subject: [PATCH 22/64] NamedTuple is immutable.

---
 sqlakeyset/paging.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 6a4481c0..f08d7570 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -510,6 +510,14 @@ def _prepare_homogeneous_page(
     result_type = orm_result_type(query)
     keys = orm_query_keys(query)
 
+    # This is unfortunately duplicated with prepare_paging, but we need 
+    """
+    selectable = orm_to_selectable(query)
+    order_cols = parse_ob_clause(selectable)
+    if backwards:
+        order_cols = [c.reversed for c in order_cols]
+    """
+
     # Could we order by page identifier to do the page collation in the DB?
 
     paging_query = prepare_paging(
@@ -521,12 +529,13 @@ def _prepare_homogeneous_page(
         dialect=query.session.get_bind().dialect,
     )
     query = paging_query.query
-    paging_query.query = paging_query.query.add_columns(
+    query = query.add_columns(
         literal_column(str(page_identifier)).label("_page_identifier"),
         func.ROW_NUMBER().over(
             order_by=[c.element for c in paging_query.order_columns]
         ).label("_row_number")
     )
+    paging_query = _PagingQuery(query, *paging_query[1:])
 
     def page_from_rows(rows):
         return orm_page_from_rows(

From 3909554c4671e580818342a18c8a22688edb4bca Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:05:26 -0700
Subject: [PATCH 23/64] Trailing whitespace.

---
 sqlakeyset/paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index f08d7570..38a7df24 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -510,7 +510,7 @@ def _prepare_homogeneous_page(
     result_type = orm_result_type(query)
     keys = orm_query_keys(query)
 
-    # This is unfortunately duplicated with prepare_paging, but we need 
+    # This is unfortunately duplicated with prepare_paging, but we need
     """
     selectable = orm_to_selectable(query)
     order_cols = parse_ob_clause(selectable)

From 3393641d12aca68542d8202cd2c1bb92c1e0a54f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:16:03 -0700
Subject: [PATCH 24/64] Use uo instead of element to get ordering right for
 ROW_NUMBER.

---
 sqlakeyset/paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 38a7df24..f3f08c35 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -532,7 +532,7 @@ def _prepare_homogeneous_page(
     query = query.add_columns(
         literal_column(str(page_identifier)).label("_page_identifier"),
         func.ROW_NUMBER().over(
-            order_by=[c.element for c in paging_query.order_columns]
+            order_by=[c.uo for c in paging_query.order_columns]
         ).label("_row_number")
     )
     paging_query = _PagingQuery(query, *paging_query[1:])

From f985063a662878547322f5375c4e5578be3da41c Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:24:48 -0700
Subject: [PATCH 25/64] Use deque for extendleft functionality.

---
 tests/test_paging.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index ef582e4e..27702734 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -13,6 +13,7 @@
 docker containers. (Available python versions are 3.7, 3.8, 3.9, 3.10, 3.11 and
 valid sqlalchemy versions are 1.3.0, 1.4.0, 2.0.0.)"""
 import warnings
+from collections import deque
 from dataclasses import dataclass
 from packaging import version
 from typing import Optional, Tuple, Union
@@ -59,7 +60,7 @@
 class _PageTracker:
     query: Query
     unpaged: list
-    gathered: list
+    gathered: deque
     backwards: bool
     page: Tuple[Union[MarkerLike, str], bool]
     page_with_paging: Optional[Page] = None
@@ -75,7 +76,7 @@ def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_
     assert paging.current == page
 
     if backwards:
-        gathered[:0] = page_with_paging
+        gathered.extendleft(reversed(page_with_paging))
     else:
         gathered.extend(page_with_paging)
 
@@ -100,7 +101,7 @@ def check_multiple_paging_orm(qs):
     page_trackers = [
         _PageTracker(
             query=q,
-            gathered=[],
+            gathered=deque(),
             backwards=(i % 2 == 0),
             page=(None, i % 2 == 0),
             unpaged=q.all(),
@@ -122,7 +123,7 @@ def check_multiple_paging_orm(qs):
             page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 1)
             if page is None:
                 # Ensure union of pages is original q.all()
-                assert t.gathered == t.unpaged
+                assert list(t.gathered) == t.unpaged
                 page_trackers.remove(t)
 
             t.page = page
@@ -135,7 +136,7 @@ def check_paging_orm(q):
 
     for backwards in [False, True]:
         for per_page in item_counts:
-            gathered = []
+            gathered = deque()
 
             page = None, backwards
 
@@ -149,7 +150,7 @@ def check_paging_orm(q):
                     break
 
             # Ensure union of pages is original q.all()
-            assert gathered == unpaged
+            assert list(gathered) == unpaged
 
 
 def check_paging_core(selectable, s):

From e5feac2c5f9e014b4adcb58b1e607e34513de0ff Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:30:07 -0700
Subject: [PATCH 26/64] Debugging info.

---
 sqlakeyset/paging.py | 1 -
 tests/test_paging.py | 3 ++-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index f3f08c35..0f211f42 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -474,7 +474,6 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     query = prepared_queries[0].paging_query.query
     query = query.union_all(*[p.paging_query.query for p in prepared_queries[1:]]).order_by(text("_page_identifier"), text("_row_number"))
 
-    print(query)
     results = query.all()
 
     # We need to make sure there's an entry for every page in case some return
diff --git a/tests/test_paging.py b/tests/test_paging.py
index 27702734..a0e440f3 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -81,9 +81,10 @@ def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_
         gathered.extend(page_with_paging)
 
     if len(gathered) < len(unpaged):
+        print(f"{len(gathered)} < {len(unpaged)}")
         # Ensure each page is the correct size
-        assert paging.has_further
         assert len(page_with_paging) == per_page
+        assert paging.has_further
     else:
         assert not paging.has_further
 

From 46248d252f7a1da5d0c9438dfad11aab2ffede20 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:43:04 -0700
Subject: [PATCH 27/64] Testing.

---
 tests/test_paging.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index a0e440f3..c76e7080 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -114,14 +114,15 @@ def check_multiple_paging_orm(qs):
             t.page = unserialize_bookmark(serialize_bookmark(t.page))
 
         page_requests = [
-            PageRequest(query=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
+            PageRequest(query=t.query, per_page=i + 2, page=t.page) for i, t in enumerate(page_trackers)
         ]
         pages_with_paging = get_homogeneous_pages(page_requests)
         for p, t in zip(pages_with_paging, page_trackers):
             t.page_with_paging = p
+            print(p)
 
         for i, t in enumerate(list(page_trackers)):
-            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 1)
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 2)
             if page is None:
                 # Ensure union of pages is original q.all()
                 assert list(t.gathered) == t.unpaged

From c5a606e065a7b1cb6952a9cbd81e8a410f904692 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:51:12 -0700
Subject: [PATCH 28/64] Add before preparing paging.

---
 sqlakeyset/paging.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 0f211f42..17ccf83f 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -510,13 +510,17 @@ def _prepare_homogeneous_page(
     keys = orm_query_keys(query)
 
     # This is unfortunately duplicated with prepare_paging, but we need
-    """
     selectable = orm_to_selectable(query)
     order_cols = parse_ob_clause(selectable)
     if backwards:
         order_cols = [c.reversed for c in order_cols]
-    """
 
+    query = query.add_columns(
+        literal_column(str(page_identifier)).label("_page_identifier"),
+        func.ROW_NUMBER().over(
+            order_by=[c.uo for c in order_cols]
+        ).label("_row_number")
+    )
     # Could we order by page identifier to do the page collation in the DB?
 
     paging_query = prepare_paging(
@@ -528,12 +532,6 @@ def _prepare_homogeneous_page(
         dialect=query.session.get_bind().dialect,
     )
     query = paging_query.query
-    query = query.add_columns(
-        literal_column(str(page_identifier)).label("_page_identifier"),
-        func.ROW_NUMBER().over(
-            order_by=[c.uo for c in paging_query.order_columns]
-        ).label("_row_number")
-    )
     paging_query = _PagingQuery(query, *paging_query[1:])
 
     def page_from_rows(rows):

From 3ccdd3e1563984faed0a68e0d984843482496d24 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 07:54:33 -0700
Subject: [PATCH 29/64] author_id is nullable which doesn't work with paging.

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index c76e7080..fea4bd87 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -426,9 +426,9 @@ def test_orm_joined_inheritance(joined_inheritance_dburl):
 def test_orm_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
-            s.query(Book).order_by(Book.author_id, Book.id),
+            s.query(Book).order_by(Book.name, Book.id),
             s.query(Book).filter(Book.author_id == 1).order_by(Book.id),
-            s.query(Book).order_by(Book.author_id, Book.id.desc()),
+            s.query(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_orm(qs=qs)
 

From 0e7cc0bcfce403720017e93aef7d3f7e8271f71d Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 08:10:28 -0700
Subject: [PATCH 30/64] Actually end the test on success.

---
 tests/test_paging.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index fea4bd87..fbaca2d6 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -127,9 +127,13 @@ def check_multiple_paging_orm(qs):
                 # Ensure union of pages is original q.all()
                 assert list(t.gathered) == t.unpaged
                 page_trackers.remove(t)
+                continue
 
             t.page = page
 
+        if not page_trackers:
+            break
+
 
 def check_paging_orm(q):
     item_counts = range(1, 12)

From 13789365d2a591c01b6c414f138d10f003726c1c Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 09:13:29 -0700
Subject: [PATCH 31/64] Add a test for fetching columns.

---
 sqlakeyset/paging.py |  6 ++++--
 tests/test_paging.py | 16 ++++++++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 17ccf83f..3cbbac5c 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -504,12 +504,15 @@ def _prepare_homogeneous_page(
     place, backwards = process_args(request.after, request.before, request.page)
 
     # Grab result_type and keys before adding the _page_identifier so that
-    # it isn't included in the results.
+    # it isn't included in the results. page_from_rows will slice the resulting
+    # row based on the length of keys
     query = request.query
     result_type = orm_result_type(query)
     keys = orm_query_keys(query)
 
     # This is unfortunately duplicated with prepare_paging, but we need
+    # to get it to add the columns *before* we do the other query wrangling
+    # inside prepare_paging.
     selectable = orm_to_selectable(query)
     order_cols = parse_ob_clause(selectable)
     if backwards:
@@ -521,7 +524,6 @@ def _prepare_homogeneous_page(
             order_by=[c.uo for c in order_cols]
         ).label("_row_number")
     )
-    # Could we order by page identifier to do the page collation in the DB?
 
     paging_query = prepare_paging(
         q=query,
diff --git a/tests/test_paging.py b/tests/test_paging.py
index fbaca2d6..1021adf6 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -81,7 +81,6 @@ def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_
         gathered.extend(page_with_paging)
 
     if len(gathered) < len(unpaged):
-        print(f"{len(gathered)} < {len(unpaged)}")
         # Ensure each page is the correct size
         assert len(page_with_paging) == per_page
         assert paging.has_further
@@ -114,15 +113,14 @@ def check_multiple_paging_orm(qs):
             t.page = unserialize_bookmark(serialize_bookmark(t.page))
 
         page_requests = [
-            PageRequest(query=t.query, per_page=i + 2, page=t.page) for i, t in enumerate(page_trackers)
+            PageRequest(query=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
         ]
         pages_with_paging = get_homogeneous_pages(page_requests)
         for p, t in zip(pages_with_paging, page_trackers):
             t.page_with_paging = p
-            print(p)
 
         for i, t in enumerate(list(page_trackers)):
-            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 2)
+            page = assert_paging_orm(t.page_with_paging, t.gathered, t.backwards, t.unpaged, t.page, i + 1)
             if page is None:
                 # Ensure union of pages is original q.all()
                 assert list(t.gathered) == t.unpaged
@@ -437,6 +435,16 @@ def test_orm_multiple_pages(no_sqlite_dburl):
         check_multiple_paging_orm(qs=qs)
 
 
+def test_orm_multiple_pages_select_columns(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        qs = [
+            s.query(Book).order_by(Book.name, Book.id),
+            s.query(Book.name, Book.id).filter(Book.author_id == 1).order_by(Book.id),
+            s.query(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
+        ]
+        check_multiple_paging_orm(qs=qs)
+
+
 def test_orm_multiple_pages_one_query(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [

From b610c69435fafb7604fbb3d71834a47064409fbe Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 09:18:06 -0700
Subject: [PATCH 32/64] Make test homogeneous.

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 1021adf6..5124d267 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -438,8 +438,8 @@ def test_orm_multiple_pages(no_sqlite_dburl):
 def test_orm_multiple_pages_select_columns(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
-            s.query(Book).order_by(Book.name, Book.id),
-            s.query(Book.name, Book.id).filter(Book.author_id == 1).order_by(Book.id),
+            s.query(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id),
+            s.query(Book.name, Book.author_id, Book.id).filter(Book.author_id == 1).order_by(Book.id),
             s.query(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_orm(qs=qs)

From d46719f8e754479d3885f7516dac938f7190c6eb Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 09:30:08 -0700
Subject: [PATCH 33/64] Move page_identifier inside prepare_paging.

---
 sqlakeyset/paging.py | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 3cbbac5c..4bebeecc 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -24,7 +24,7 @@
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
 from sqlalchemy.orm.query import Query
-from sqlalchemy.sql.expression import ColumnElement, literal_column
+from sqlalchemy.sql.expression import ColumnElement, literal
 from sqlalchemy.sql.selectable import Select
 
 from .columns import OC, MappedOrderColumn, find_order_key, parse_ob_clause
@@ -155,6 +155,7 @@ def prepare_paging(
     backwards: bool,
     orm: Literal[True],
     dialect: Dialect,
+    page_identifier: Optional[int] = None,
 ) -> _PagingQuery:
     ...
 
@@ -167,6 +168,7 @@ def prepare_paging(
     backwards: bool,
     orm: Literal[False],
     dialect: Dialect,
+    page_identifier: Optional[int] = None,
 ) -> _PagingSelect:
     ...
 
@@ -178,6 +180,7 @@ def prepare_paging(
     backwards: bool,
     orm: bool,
     dialect: Dialect,
+    page_identifier: Optional[int] = None,
 ) -> Union[_PagingQuery, _PagingSelect]:
     if orm:
         if not isinstance(q, Query):
@@ -206,6 +209,15 @@ def prepare_paging(
     extra_columns = [
         col.extra_column for col in mapped_ocols if col.extra_column is not None
     ]
+
+    # page_identifier is used for fetching multiple pages.
+    if page_identifier is not None:
+        extra_columns += [
+            literal(page_identifier).label("_page_identifier"),
+            func.ROW_NUMBER().over(
+                order_by=[c.uo for c in order_cols]
+            ).label("_row_number"),
+        ]
     if hasattr(q, "add_columns"):  # ORM or SQLAlchemy 1.4+
         q = q.add_columns(*extra_columns)
     else:
@@ -498,33 +510,12 @@ class _PreparedQuery:
 def _prepare_homogeneous_page(
         request: PageRequest[_TP], page_identifier: int
 ) -> _PreparedQuery:
-    """page_identifier MUST be a trusted int, as it is not escaped."""
-    # Should have no effect if called correctly, but let's be extra safe.
-    page_identifier = int(page_identifier)
     place, backwards = process_args(request.after, request.before, request.page)
 
-    # Grab result_type and keys before adding the _page_identifier so that
-    # it isn't included in the results. page_from_rows will slice the resulting
-    # row based on the length of keys
     query = request.query
     result_type = orm_result_type(query)
     keys = orm_query_keys(query)
 
-    # This is unfortunately duplicated with prepare_paging, but we need
-    # to get it to add the columns *before* we do the other query wrangling
-    # inside prepare_paging.
-    selectable = orm_to_selectable(query)
-    order_cols = parse_ob_clause(selectable)
-    if backwards:
-        order_cols = [c.reversed for c in order_cols]
-
-    query = query.add_columns(
-        literal_column(str(page_identifier)).label("_page_identifier"),
-        func.ROW_NUMBER().over(
-            order_by=[c.uo for c in order_cols]
-        ).label("_row_number")
-    )
-
     paging_query = prepare_paging(
         q=query,
         per_page=request.per_page,
@@ -532,9 +523,8 @@ def _prepare_homogeneous_page(
         backwards=backwards,
         orm=True,
         dialect=query.session.get_bind().dialect,
+        page_identifier=page_identifier,
     )
-    query = paging_query.query
-    paging_query = _PagingQuery(query, *paging_query[1:])
 
     def page_from_rows(rows):
         return orm_page_from_rows(

From bdac930c82ea4c4c09843b6160eb7ff448c0609d Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:09:11 -0700
Subject: [PATCH 34/64] Add select_homogeneous_pages and refactor tests.

---
 sqlakeyset/__init__.py |   2 +-
 sqlakeyset/paging.py   | 107 +++++++++++++++++++++++++++++++++++++----
 tests/test_paging.py   |  43 ++++++++++-------
 3 files changed, 123 insertions(+), 29 deletions(-)

diff --git a/sqlakeyset/__init__.py b/sqlakeyset/__init__.py
index 6b286d8d..4996f35e 100644
--- a/sqlakeyset/__init__.py
+++ b/sqlakeyset/__init__.py
@@ -1,4 +1,4 @@
-from .paging import get_homogeneous_pages, get_page, select_page, InvalidPage, PageRequest
+from .paging import get_homogeneous_pages, get_page, select_homogeneous_pages, select_page, InvalidPage, OrmPageRequest, PageRequest
 from .results import (
     Page,
     Paging,
diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 4bebeecc..48da5c32 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -291,11 +291,13 @@ def core_get_page(
     :param backwards: If ``True``, reverse pagination direction.
     :returns: :class:`Page`
     """
-    # We need the result schema for the *original* query in order to properly
-    # trim off our extra_columns. As far as I can tell, this is the only
+    # In SQLAlchemy 1.3, we need the result schema for the *original* query in order
+    # to properly trim off our extra_columns. As far as I can tell, this is the only
     # way to get it without copy-pasting chunks of the sqlalchemy internals.
     # LIMIT 0 to minimize database load (though the fact that a round trip to
     # the DB has to happen at all is regrettable).
+    #
+    # Thankfully this is obsolete in 1.4+
     result_type = core_result_type(selectable, s)
     sel = prepare_paging(
         q=selectable,
@@ -456,7 +458,7 @@ def get_page(
 
 
 @dataclass
-class PageRequest(Generic[_TP]):
+class OrmPageRequest(Generic[_TP]):
     """See ``get_page()`` documentation for parameter explanations."""
     query: Query[_TP]
     per_page: int = PER_PAGE_DEFAULT
@@ -465,7 +467,17 @@ class PageRequest(Generic[_TP]):
     page: Optional[Union[MarkerLike, str]] = None
 
 
-def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP]]]:
+@dataclass
+class PageRequest(Generic[_TP]):
+    """See ``select_page()`` documentation for parameter explanations."""
+    selectable: Select[_TP]
+    per_page: int = PER_PAGE_DEFAULT
+    after: OptionalKeyset = None
+    before: OptionalKeyset = None
+    page: Optional[Union[MarkerLike, str]] = None
+
+
+def get_homogeneous_pages(requests: list[OrmPageRequest[_TP]]) -> list[Page[Row[_TP]]]:
     """Get multiple pages of results for homogeneous legacy ORM queries.
 
     This only involves a single round trip to the database. To do that, under the
@@ -481,10 +493,14 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     if not requests:
         return []
 
-    prepared_queries = [_prepare_homogeneous_page(request, i) for i, request in enumerate(requests)]
+    prepared_queries = [
+        _orm_prepare_homogeneous_page(request, i) for i, request in enumerate(requests)
+    ]
 
     query = prepared_queries[0].paging_query.query
-    query = query.union_all(*[p.paging_query.query for p in prepared_queries[1:]]).order_by(text("_page_identifier"), text("_row_number"))
+    query = query.union_all(
+        *[p.paging_query.query for p in prepared_queries[1:]]
+    ).order_by(text("_page_identifier"), text("_row_number"))
 
     results = query.all()
 
@@ -501,14 +517,85 @@ def get_homogeneous_pages(requests: list[PageRequest[_TP]]) -> list[Page[Row[_TP
     return pages
 
 
+def select_homogeneous_pages(
+    requests: list[PageRequest[_TP]], s: Union[Session, Connection]
+) -> list[Page[Row[_TP]]]:
+    """Get multiple pages of results for homogeneous legacy ORM queries.
+
+    This only involves a single round trip to the database. To do that, under the
+    hood it generates a UNION ALL. That means each query must select exactly the
+    same columns. They may have different filters or ordering, but must result in
+    selecting the same columns with the same names.
+
+    Note: This requires the underlying database to support ORDER BY and LIMIT
+    statements in components of a compound select, which SQLite does not.
+
+    Resulting pages are returned in the same order as the original page requests.
+    """
+    if not requests:
+        return []
+
+    prepared_queries = [_core_prepare_homogeneous_page(request, s, i) for i, request in enumerate(requests)]
+
+    select = union_all(*[p.paging_query.select for p in prepared_queries])
+    selected = s.execute(sel.select)
+
+    results = query.fetchall()
+
+    # We need to make sure there's an entry for every page in case some return
+    # empty.
+    page_to_rows = {i: list() for i in range(len(requests))}
+    for row in results:
+        page_to_rows[row._page_identifier].append(row)
+
+    pages = []
+    for i in range(len(requests)):
+        rows = page_to_rows[i]
+        pages.append(prepared_queries[i].page_from_rows(rows, selected))
+    return pages
+
+
 @dataclass
 class _PreparedQuery:
-    paging_query: _PagingQuery
-    page_from_rows: Callable[[list[Row[_TP]]], Page[Row[_TP]]]
+    paging_query: Union[_PagingQuery, _PagingSelect]
+    page_from_rows: Callable[..., Page[Row[_TP]]]
+
+
+def _core_prepare_homogeneous_page(
+    request: PageRequest[_TP], s: Union[Session, Connection], page_identifier: int
+) -> _PreparedQuery:
+    place, backwards = process_args(request.after, request.before, request.page)
+
+    selectable = request.selectable
+    result_type = core_result_type(selectable, s)
+    sel = prepare_paging(
+        q=selectable,
+        per_page=request.per_page,
+        place=place,
+        backwards=backwards,
+        orm=False,
+        dialect=get_bind(q=selectable, s=s).dialect,
+    )
+    def page_from_rows(rows, selected):
+        keys = list(selected.keys())
+        N = len(keys) - len(sel.extra_columns)
+        keys = keys[:N]
+        page = core_page_from_rows(
+            sel,
+            rows,
+            keys,
+            result_type,
+            request.per_page,
+            backwards,
+            current_place=place,
+        )
+        return page
+
+    return _PreparedQuery(paging_query=sel, page_from_rows=page_from_rows)
 
 
-def _prepare_homogeneous_page(
-        request: PageRequest[_TP], page_identifier: int
+def _orm_prepare_homogeneous_page(
+    request: OrmPageRequest[_TP], page_identifier: int
 ) -> _PreparedQuery:
     place, backwards = process_args(request.after, request.before, request.page)
 
diff --git a/tests/test_paging.py b/tests/test_paging.py
index 5124d267..3ca1ece3 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -33,6 +33,7 @@
     serialize_bookmark,
     unserialize_bookmark,
     InvalidPage,
+    OrmPageRequest,
     PageRequest,
 )
 from sqlakeyset.paging import process_args
@@ -113,7 +114,7 @@ def check_multiple_paging_orm(qs):
             t.page = unserialize_bookmark(serialize_bookmark(t.page))
 
         page_requests = [
-            PageRequest(query=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
+            OrmPageRequest(query=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
         ]
         pages_with_paging = get_homogeneous_pages(page_requests)
         for p, t in zip(pages_with_paging, page_trackers):
@@ -157,6 +158,26 @@ def check_paging_orm(q):
             assert list(gathered) == unpaged
 
 
+def assert_paging_core(page_with_paging, gathered, backwards, unpaged, page, per_page):
+    paging = page_with_paging.paging
+
+    assert paging.current == page
+    assert page_with_paging.keys() == result.keys()
+
+    if backwards:
+        gathered.extendleft(reversed(page_with_paging))
+    else:
+        gathered.extend(page_with_paging)
+
+    if not page_with_paging:
+        assert not paging.has_further
+        assert paging.further == paging.current
+        assert paging.current_opposite == (None, not paging.backwards)
+        return None
+
+    return paging.further
+
+
 def check_paging_core(selectable, s):
     item_counts = range(1, 12)
 
@@ -165,7 +186,7 @@ def check_paging_core(selectable, s):
 
     for backwards in [False, True]:
         for per_page in item_counts:
-            gathered = []
+            gathered = deque()
 
             page = None, backwards
 
@@ -176,22 +197,8 @@ def check_paging_core(selectable, s):
                 page_with_paging = select_page(
                     s, selectable, per_page=per_page, page=serialized_page
                 )
-                paging = page_with_paging.paging
-
-                assert paging.current == page
-                assert page_with_paging.keys() == result.keys()
-
-                if backwards:
-                    gathered = page_with_paging + gathered
-                else:
-                    gathered = gathered + page_with_paging
-
-                page = paging.further
-
-                if not page_with_paging:
-                    assert not paging.has_further
-                    assert paging.further == paging.current
-                    assert paging.current_opposite == (None, not paging.backwards)
+                page = assert_paging_core(page_with_paging, gathered, backwards, unpaged, page, per_page)
+                if page is None:
                     break
 
             assert gathered == unpaged

From 1127c0f187dd8e75bd8c50c8301b3c44c710a996 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:17:33 -0700
Subject: [PATCH 35/64] flake8 fixes.

---
 sqlakeyset/__init__.py | 12 +++++++++++-
 sqlakeyset/paging.py   | 11 +++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/sqlakeyset/__init__.py b/sqlakeyset/__init__.py
index 4996f35e..47737356 100644
--- a/sqlakeyset/__init__.py
+++ b/sqlakeyset/__init__.py
@@ -1,4 +1,12 @@
-from .paging import get_homogeneous_pages, get_page, select_homogeneous_pages, select_page, InvalidPage, OrmPageRequest, PageRequest
+from .paging import (
+    get_homogeneous_pages,
+    get_page,
+    select_homogeneous_pages,
+    select_page,
+    InvalidPage,
+    OrmPageRequest,
+    PageRequest,
+)
 from .results import (
     Page,
     Paging,
@@ -17,11 +25,13 @@
 __all__ = [
     "get_homogeneous_pages",
     "get_page",
+    "select_homogeneous_pages",
     "select_page",
     "serialize_bookmark",
     "unserialize_bookmark",
     "Page",
     "PageRequest",
+    "OrmPageRequest",
     "Paging",
     "Keyset",
     "Marker",
diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 48da5c32..4e61e854 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -24,7 +24,7 @@
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
 from sqlalchemy.orm.query import Query
-from sqlalchemy.sql.expression import ColumnElement, literal
+from sqlalchemy.sql.expression import ColumnElement, literal, union_all
 from sqlalchemy.sql.selectable import Select
 
 from .columns import OC, MappedOrderColumn, find_order_key, parse_ob_clause
@@ -537,10 +537,12 @@ def select_homogeneous_pages(
 
     prepared_queries = [_core_prepare_homogeneous_page(request, s, i) for i, request in enumerate(requests)]
 
-    select = union_all(*[p.paging_query.select for p in prepared_queries])
-    selected = s.execute(sel.select)
+    select = union_all(
+        *[p.paging_query.select for p in prepared_queries]
+    ).order_by(text("_page_identifier"), text("_row_number"))
+    selected = s.execute(select)
 
-    results = query.fetchall()
+    results = selected.fetchall()
 
     # We need to make sure there's an entry for every page in case some return
     # empty.
@@ -576,6 +578,7 @@ def _core_prepare_homogeneous_page(
         orm=False,
         dialect=get_bind(q=selectable, s=s).dialect,
     )
+
     def page_from_rows(rows, selected):
         keys = list(selected.keys())
         N = len(keys) - len(sel.extra_columns)

From 24943ea7789b304bc99059b68815c29841bd4926 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:20:27 -0700
Subject: [PATCH 36/64] More flake8.

---
 tests/test_paging.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 3ca1ece3..86667a0a 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -34,7 +34,6 @@
     unserialize_bookmark,
     InvalidPage,
     OrmPageRequest,
-    PageRequest,
 )
 from sqlakeyset.paging import process_args
 from sqlakeyset.results import Page
@@ -158,7 +157,7 @@ def check_paging_orm(q):
             assert list(gathered) == unpaged
 
 
-def assert_paging_core(page_with_paging, gathered, backwards, unpaged, page, per_page):
+def assert_paging_core(page_with_paging, gathered, backwards, result, page, per_page):
     paging = page_with_paging.paging
 
     assert paging.current == page
@@ -197,7 +196,7 @@ def check_paging_core(selectable, s):
                 page_with_paging = select_page(
                     s, selectable, per_page=per_page, page=serialized_page
                 )
-                page = assert_paging_core(page_with_paging, gathered, backwards, unpaged, page, per_page)
+                page = assert_paging_core(page_with_paging, gathered, backwards, result, page, per_page)
                 if page is None:
                     break
 

From 5bb4c5d7d34d046fee36bbaca70d6ba305404363 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:23:12 -0700
Subject: [PATCH 37/64] Convert deque to list.

---
 tests/test_paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 86667a0a..340cc654 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -200,7 +200,7 @@ def check_paging_core(selectable, s):
                 if page is None:
                     break
 
-            assert gathered == unpaged
+            assert list(gathered) == unpaged
 
 
 def test_orm_query1(dburl):

From 29985c410eaaeeabb2abf375f9bbe71c0f8171ed Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:34:48 -0700
Subject: [PATCH 38/64] Test select_homogeneous_pages.

---
 tests/test_paging.py | 123 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 97 insertions(+), 26 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 340cc654..8472381a 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -16,7 +16,7 @@
 from collections import deque
 from dataclasses import dataclass
 from packaging import version
-from typing import Optional, Tuple, Union
+from typing import Any, Optional, Tuple, Union
 
 import pytest
 import sqlalchemy
@@ -25,6 +25,7 @@
     desc,
     func,
 )
+from sqlalchemy.sql.selectable import Select
 
 from sqlakeyset import (
     get_page,
@@ -58,8 +59,9 @@
 
 @dataclass
 class _PageTracker:
-    query: Query
+    query: Union[Query, Select]
     unpaged: list
+    selected: Any
     gathered: deque
     backwards: bool
     page: Tuple[Union[MarkerLike, str], bool]
@@ -97,6 +99,30 @@ def assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_
     return paging.further
 
 
+def check_paging_orm(q):
+    item_counts = range(1, 12)
+
+    unpaged = q.all()
+
+    for backwards in [False, True]:
+        for per_page in item_counts:
+            gathered = deque()
+
+            page = None, backwards
+
+            while True:
+                serialized_page = serialize_bookmark(page)
+                page = unserialize_bookmark(serialized_page)
+
+                page_with_paging = get_page(q, per_page=per_page, page=serialized_page)
+                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page)
+                if page is None:
+                    break
+
+            # Ensure union of pages is original q.all()
+            assert list(gathered) == unpaged
+
+
 def check_multiple_paging_orm(qs):
     page_trackers = [
         _PageTracker(
@@ -133,30 +159,6 @@ def check_multiple_paging_orm(qs):
             break
 
 
-def check_paging_orm(q):
-    item_counts = range(1, 12)
-
-    unpaged = q.all()
-
-    for backwards in [False, True]:
-        for per_page in item_counts:
-            gathered = deque()
-
-            page = None, backwards
-
-            while True:
-                serialized_page = serialize_bookmark(page)
-                page = unserialize_bookmark(serialized_page)
-
-                page_with_paging = get_page(q, per_page=per_page, page=serialized_page)
-                page = assert_paging_orm(page_with_paging, gathered, backwards, unpaged, page, per_page)
-                if page is None:
-                    break
-
-            # Ensure union of pages is original q.all()
-            assert list(gathered) == unpaged
-
-
 def assert_paging_core(page_with_paging, gathered, backwards, result, page, per_page):
     paging = page_with_paging.paging
 
@@ -203,6 +205,43 @@ def check_paging_core(selectable, s):
             assert list(gathered) == unpaged
 
 
+def check_multiple_paging_core(qs, s):
+    page_trackers = [
+        _PageTracker(
+            query=q,
+            gathered=deque(),
+            backwards=(i % 2 == 0),
+            page=(None, i % 2 == 0),
+            selected=s.execute(q),
+            unpaged=s.execute(q).fetchall(),
+        )
+        for i, q in enumerate(qs)
+    ]
+    while True:
+        for t in page_trackers:
+            t.page = unserialize_bookmark(serialize_bookmark(t.page))
+
+        page_requests = [
+            PageRequest(selectable=t.query, per_page=i + 1, page=t.page) for i, t in enumerate(page_trackers)
+        ]
+        pages_with_paging = select_homogeneous_pages(page_requests, s)
+        for p, t in zip(pages_with_paging, page_trackers):
+            t.page_with_paging = p
+
+        for i, t in enumerate(list(page_trackers)):
+            page = assert_paging_core(t.page_with_paging, t.gathered, t.backwards, t.selected, t.page, i + 1)
+            if page is None:
+                # Ensure union of pages is original q.all()
+                assert list(t.gathered) == t.unpaged
+                page_trackers.remove(t)
+                continue
+
+            t.page = page
+
+        if not page_trackers:
+            break
+
+
 def test_orm_query1(dburl):
     spec = [desc(Book.b), Book.d, Book.id]
 
@@ -463,6 +502,38 @@ def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
 
+def test_core_multiple_pages(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        qs = [
+            select(Book).order_by(Book.name, Book.id),
+            select(Book).filter(Book.author_id == 1).order_by(Book.id),
+            select(Book).order_by(Book.name, Book.id.desc()),
+        ]
+        check_multiple_paging_core(qs=qs, s=s)
+
+
+def test_core_multiple_pages_select_columns(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        qs = [
+            select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id),
+            select(Book.name, Book.author_id, Book.id).filter(Book.author_id == 1).order_by(Book.id),
+            select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
+        ]
+        check_multiple_paging_core(qs=qs, s=s)
+
+
+def test_core_multiple_pages_one_query(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        qs = [
+            select(Book).order_by(Book.id),
+        ]
+        check_multiple_paging_core(qs=qs, s=s)
+
+
+def test_core_multiple_pages_empty_queries():
+    assert select_homogeneous_pages([]) == []
+
+
 def test_core(dburl):
     selectable = (
         select(Book.b, Book.d, Book.id, Book.c)

From 87a6a08dfcf57564522aa4243be5486c3d192959 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:41:55 -0700
Subject: [PATCH 39/64] Flake 8 violations.

---
 tests/test_paging.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 8472381a..3b0393e4 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -28,13 +28,15 @@
 from sqlalchemy.sql.selectable import Select
 
 from sqlakeyset import (
-    get_page,
     get_homogeneous_pages,
+    get_page,
+    select_homogeneous_pages,
     select_page,
     serialize_bookmark,
     unserialize_bookmark,
     InvalidPage,
     OrmPageRequest,
+    PageRequest,
 )
 from sqlakeyset.paging import process_args
 from sqlakeyset.results import Page

From 993e45fd0b21e3ed790e7dadac9d171e8a73a42b Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:50:02 -0700
Subject: [PATCH 40/64] Fix default.

---
 tests/test_paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 3b0393e4..f921cf30 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -63,7 +63,7 @@
 class _PageTracker:
     query: Union[Query, Select]
     unpaged: list
-    selected: Any
+    selected: Any = None
     gathered: deque
     backwards: bool
     page: Tuple[Union[MarkerLike, str], bool]

From 23ec6da81d96f23a51761f219d48246cf9e1b510 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:51:11 -0700
Subject: [PATCH 41/64] non-default before default.

---
 tests/test_paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index f921cf30..44201593 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -63,10 +63,10 @@
 class _PageTracker:
     query: Union[Query, Select]
     unpaged: list
-    selected: Any = None
     gathered: deque
     backwards: bool
     page: Tuple[Union[MarkerLike, str], bool]
+    selected: Any = None
     page_with_paging: Optional[Page] = None
 
 

From aff47d87f58ca44a8d06955a1798f912db7e68e9 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 11:53:44 -0700
Subject: [PATCH 42/64] Add page_identifier

---
 sqlakeyset/paging.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 4e61e854..2f61b493 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -577,6 +577,7 @@ def _core_prepare_homogeneous_page(
         backwards=backwards,
         orm=False,
         dialect=get_bind(q=selectable, s=s).dialect,
+        page_identifier=page_identifier,
     )
 
     def page_from_rows(rows, selected):

From dfee9ddee901fa13fdc326c2bdf3e7cec4527c5b Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 12:11:01 -0700
Subject: [PATCH 43/64] filter -> where.

---
 sqlakeyset/paging.py | 2 ++
 tests/test_paging.py | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 2f61b493..975741f9 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -218,6 +218,7 @@ def prepare_paging(
                 order_by=[c.uo for c in order_cols]
             ).label("_row_number"),
         ]
+
     if hasattr(q, "add_columns"):  # ORM or SQLAlchemy 1.4+
         q = q.add_columns(*extra_columns)
     else:
@@ -582,6 +583,7 @@ def _core_prepare_homogeneous_page(
 
     def page_from_rows(rows, selected):
         keys = list(selected.keys())
+        print(keys)
         N = len(keys) - len(sel.extra_columns)
         keys = keys[:N]
         page = core_page_from_rows(
diff --git a/tests/test_paging.py b/tests/test_paging.py
index 44201593..bbb4fc11 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -508,7 +508,7 @@ def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
             select(Book).order_by(Book.name, Book.id),
-            select(Book).filter(Book.author_id == 1).order_by(Book.id),
+            select(Book).where(Book.author_id == 1).order_by(Book.id),
             select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
@@ -518,7 +518,7 @@ def test_core_multiple_pages_select_columns(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
             select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id),
-            select(Book.name, Book.author_id, Book.id).filter(Book.author_id == 1).order_by(Book.id),
+            select(Book.name, Book.author_id, Book.id).where(Book.author_id == 1).order_by(Book.id),
             select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)

From 403a3977399be7cfc1ab693fd897ad699fbbe7fc Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 12:14:10 -0700
Subject: [PATCH 44/64] Add debugging.

---
 sqlakeyset/paging.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 975741f9..0138e212 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -583,9 +583,10 @@ def _core_prepare_homogeneous_page(
 
     def page_from_rows(rows, selected):
         keys = list(selected.keys())
-        print(keys)
         N = len(keys) - len(sel.extra_columns)
         keys = keys[:N]
+        print(keys)
+        print(rows[0])
         page = core_page_from_rows(
             sel,
             rows,

From ead71a30c1e0200448f11bccd7ac2368ce2115f0 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 12:17:09 -0700
Subject: [PATCH 45/64] Fix select statements.

---
 tests/test_paging.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index bbb4fc11..24c1db43 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -507,9 +507,9 @@ def test_orm_multiple_pages_empty_queries():
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
-            select(Book).order_by(Book.name, Book.id),
-            select(Book).where(Book.author_id == 1).order_by(Book.id),
-            select(Book).order_by(Book.name, Book.id.desc()),
+            select(Book.name).order_by(Book.name, Book.id),
+            select(Book.name).where(Book.author_id == 1).order_by(Book.id),
+            select(Book.name).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
 
@@ -527,7 +527,7 @@ def test_core_multiple_pages_select_columns(no_sqlite_dburl):
 def test_core_multiple_pages_one_query(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
-            select(Book).order_by(Book.id),
+            select(Book.a, Book.b).order_by(Book.id),
         ]
         check_multiple_paging_core(qs=qs, s=s)
 

From 685fca4bc2d3f08b0b7ce6136f6da8418dbe81f8 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <MatthewAlbrecht2015@gmail.com>
Date: Fri, 14 Jul 2023 12:25:09 -0700
Subject: [PATCH 46/64] Go back to Book orm.

---
 tests/test_paging.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 24c1db43..2701b741 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -507,9 +507,9 @@ def test_orm_multiple_pages_empty_queries():
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
-            select(Book.name).order_by(Book.name, Book.id),
-            select(Book.name).where(Book.author_id == 1).order_by(Book.id),
-            select(Book.name).order_by(Book.name, Book.id.desc()),
+            select(Book).order_by(Book.name, Book.id),
+            select(Book).where(Book.author_id == 1).order_by(Book.id),
+            select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
 

From ccb3e915ac214827fbe7124c650de5a3f3652266 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 11:20:39 -0700
Subject: [PATCH 47/64] add a print statement.

---
 sqlakeyset/paging.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 0138e212..41ebf1a9 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -583,9 +583,10 @@ def _core_prepare_homogeneous_page(
 
     def page_from_rows(rows, selected):
         keys = list(selected.keys())
+        print(f"pre-shrunk keys: {keys}")
         N = len(keys) - len(sel.extra_columns)
         keys = keys[:N]
-        print(keys)
+        print(f"post-shrunk keys: {keys}")
         print(rows[0])
         page = core_page_from_rows(
             sel,

From 4f62fba2bbc0c8ef3933e04569bd8bec8a3b1053 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 11:34:07 -0700
Subject: [PATCH 48/64] Start with the simplest test first.

---
 tests/test_paging.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 2701b741..a17045ea 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -503,7 +503,7 @@ def test_orm_multiple_pages_one_query(no_sqlite_dburl):
 def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
-
+"""
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
@@ -522,7 +522,7 @@ def test_core_multiple_pages_select_columns(no_sqlite_dburl):
             select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
-
+"""
 
 def test_core_multiple_pages_one_query(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:

From 43694f09ab775a33f2de3c2c901cb0d67dc13c30 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 11:37:15 -0700
Subject: [PATCH 49/64] flake8

---
 tests/test_paging.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index a17045ea..4202d873 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -503,6 +503,7 @@ def test_orm_multiple_pages_one_query(no_sqlite_dburl):
 def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
+
 """
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
@@ -524,6 +525,7 @@ def test_core_multiple_pages_select_columns(no_sqlite_dburl):
         check_multiple_paging_core(qs=qs, s=s)
 """
 
+
 def test_core_multiple_pages_one_query(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [

From 34c41b23dde8fa9a94c9fe2862f0ea6511c6a465 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 11:41:28 -0700
Subject: [PATCH 50/64] Print statement caused exception.

---
 sqlakeyset/paging.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 41ebf1a9..b32d66de 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -587,7 +587,8 @@ def page_from_rows(rows, selected):
         N = len(keys) - len(sel.extra_columns)
         keys = keys[:N]
         print(f"post-shrunk keys: {keys}")
-        print(rows[0])
+        if rows:
+            print(rows[0])
         page = core_page_from_rows(
             sel,
             rows,

From db47749535190581bc6886d10a10f7aa5d4e1ded Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 12:55:45 -0700
Subject: [PATCH 51/64] Don't double order single selects.

---
 sqlakeyset/paging.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index b32d66de..2ab8f824 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -540,7 +540,10 @@ def select_homogeneous_pages(
 
     select = union_all(
         *[p.paging_query.select for p in prepared_queries]
-    ).order_by(text("_page_identifier"), text("_row_number"))
+    )
+    if len(prepared_queries) > 1:
+        select = select.order_by(text("_page_identifier"), text("_row_number"))
+
     selected = s.execute(select)
 
     results = selected.fetchall()

From 90e9ae760eb03b3944de40fda681f958e93ae6c7 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:00:36 -0700
Subject: [PATCH 52/64] Fix test_core..._empty_queries.

---
 tests/test_paging.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 4202d873..6a054ba3 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -535,7 +535,8 @@ def test_core_multiple_pages_one_query(no_sqlite_dburl):
 
 
 def test_core_multiple_pages_empty_queries():
-    assert select_homogeneous_pages([]) == []
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        assert select_homogeneous_pages([], s) == []
 
 
 def test_core(dburl):

From 8ecb334a6aba9b525f6a0a4b6f379b8ebadc751f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:02:12 -0700
Subject: [PATCH 53/64] flake8.

---
 tests/test_paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index 6a054ba3..dd0e6d11 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -534,7 +534,7 @@ def test_core_multiple_pages_one_query(no_sqlite_dburl):
         check_multiple_paging_core(qs=qs, s=s)
 
 
-def test_core_multiple_pages_empty_queries():
+def test_core_multiple_pages_empty_queries(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         assert select_homogeneous_pages([], s) == []
 

From 6c33a0f3e3258092dbcfe869ebc0adb198458c2e Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:05:14 -0700
Subject: [PATCH 54/64] One more test.

---
 sqlakeyset/paging.py | 1 +
 tests/test_paging.py | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 2ab8f824..edbea85d 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -544,6 +544,7 @@ def select_homogeneous_pages(
     if len(prepared_queries) > 1:
         select = select.order_by(text("_page_identifier"), text("_row_number"))
 
+    print(f"Select statement: {select}")
     selected = s.execute(select)
 
     results = selected.fetchall()
diff --git a/tests/test_paging.py b/tests/test_paging.py
index dd0e6d11..eab245a4 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -513,6 +513,7 @@ def test_core_multiple_pages(no_sqlite_dburl):
             select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
+"""
 
 
 def test_core_multiple_pages_select_columns(no_sqlite_dburl):
@@ -523,7 +524,6 @@ def test_core_multiple_pages_select_columns(no_sqlite_dburl):
             select(Book.name, Book.author_id, Book.id).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
-"""
 
 
 def test_core_multiple_pages_one_query(no_sqlite_dburl):

From e230d1a421ea637de237551f4a2e5e036518dac4 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:19:08 -0700
Subject: [PATCH 55/64] Try using sub-select for key generation.

---
 sqlakeyset/paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index edbea85d..575cba86 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -558,7 +558,7 @@ def select_homogeneous_pages(
     pages = []
     for i in range(len(requests)):
         rows = page_to_rows[i]
-        pages.append(prepared_queries[i].page_from_rows(rows, selected))
+        pages.append(prepared_queries[i].page_from_rows(rows, s.execute(prepared_queries[i].paging_query.select)))
     return pages
 
 

From 0917ceb340999d0904cc28d1bd5a38be4c4da906 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:24:54 -0700
Subject: [PATCH 56/64] See if individualized selected works for select(Book)

---
 tests/test_paging.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index eab245a4..b3b93c2e 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -504,7 +504,6 @@ def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
 
-"""
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
@@ -513,7 +512,6 @@ def test_core_multiple_pages(no_sqlite_dburl):
             select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
-"""
 
 
 def test_core_multiple_pages_select_columns(no_sqlite_dburl):

From 719440c222787852d67a4119bf25244bf6d8674f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:40:24 -0700
Subject: [PATCH 57/64] Try a different way of forming the union.

---
 sqlakeyset/paging.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 575cba86..d5318667 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -538,10 +538,14 @@ def select_homogeneous_pages(
 
     prepared_queries = [_core_prepare_homogeneous_page(request, s, i) for i, request in enumerate(requests)]
 
+    """
     select = union_all(
         *[p.paging_query.select for p in prepared_queries]
     )
+    """
+    select = prepared_queries[0].paging_query.select
     if len(prepared_queries) > 1:
+        select = select.union_all(*[p.paging_query.select for p in prepared_queries[1:]])
         select = select.order_by(text("_page_identifier"), text("_row_number"))
 
     print(f"Select statement: {select}")

From e192516bfb68a08035439fc27d640c38fe89047e Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:41:38 -0700
Subject: [PATCH 58/64] flake8

---
 sqlakeyset/paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index d5318667..a8a2330f 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -24,7 +24,7 @@
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
 from sqlalchemy.orm.query import Query
-from sqlalchemy.sql.expression import ColumnElement, literal, union_all
+from sqlalchemy.sql.expression import ColumnElement, literal
 from sqlalchemy.sql.selectable import Select
 
 from .columns import OC, MappedOrderColumn, find_order_key, parse_ob_clause

From 6b596a5fe79f27745df2f0076c2fe41c57ef990f Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:44:32 -0700
Subject: [PATCH 59/64] Backtrack on testing, plus add a more fundamental test.

---
 tests/test_paging.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index b3b93c2e..f37a91ab 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -504,6 +504,7 @@ def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
 
+"""
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
@@ -512,6 +513,7 @@ def test_core_multiple_pages(no_sqlite_dburl):
             select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
+"""
 
 
 def test_core_multiple_pages_select_columns(no_sqlite_dburl):
@@ -552,6 +554,17 @@ def test_core(dburl):
         check_paging_core(selectable=selectable, s=s.connection())
 
 
+def test_core_whole_model(dburl):
+    selectable = (
+        select(Book)
+        .where(Book.d == 99)
+        .order_by(Book.id)
+    )
+
+    with S(dburl, echo=ECHO) as s:
+        check_paging_core(selectable=selectable, s=s)
+
+
 def test_core2(dburl):
     with S(dburl, echo=ECHO) as s:
         sel = select(Book.score).order_by(Book.id)

From 806ef9d2a6178db7562a9358a6e74bc5e2bc2bc0 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:47:46 -0700
Subject: [PATCH 60/64] Add a test.

---
 tests/test_paging.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/test_paging.py b/tests/test_paging.py
index f37a91ab..e206a71e 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -534,6 +534,14 @@ def test_core_multiple_pages_one_query(no_sqlite_dburl):
         check_multiple_paging_core(qs=qs, s=s)
 
 
+def test_core_multiple_pages_one_query_whole_model(no_sqlite_dburl):
+    with S(no_sqlite_dburl, echo=ECHO) as s:
+        qs = [
+            select(Book).order_by(Book.id),
+        ]
+        check_multiple_paging_core(qs=qs, s=s)
+
+
 def test_core_multiple_pages_empty_queries(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         assert select_homogeneous_pages([], s) == []

From fa5fd494817f9dfed9a6ab5a936d7c599c09d142 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 13:55:14 -0700
Subject: [PATCH 61/64] Only execute one subselect as necessary.

---
 sqlakeyset/paging.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index a8a2330f..b3dddb65 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -538,14 +538,10 @@ def select_homogeneous_pages(
 
     prepared_queries = [_core_prepare_homogeneous_page(request, s, i) for i, request in enumerate(requests)]
 
-    """
     select = union_all(
         *[p.paging_query.select for p in prepared_queries]
     )
-    """
-    select = prepared_queries[0].paging_query.select
     if len(prepared_queries) > 1:
-        select = select.union_all(*[p.paging_query.select for p in prepared_queries[1:]])
         select = select.order_by(text("_page_identifier"), text("_row_number"))
 
     print(f"Select statement: {select}")
@@ -560,9 +556,17 @@ def select_homogeneous_pages(
         page_to_rows[row._page_identifier].append(row)
 
     pages = []
+    # This is an unfortunate side effect of union_all. It appears we union_all
+    # a bunch of selects, it changes the "keys" on us in cases where the column
+    # name and python attribute don't match. So we have to execute the first
+    # query standalone to ge the correct keys.
+    subselect_result = (
+        s.execute(prepared_queries[0].paging_query.select)
+        if len(prepared_queries) > 1 else selected
+    )
     for i in range(len(requests)):
         rows = page_to_rows[i]
-        pages.append(prepared_queries[i].page_from_rows(rows, s.execute(prepared_queries[i].paging_query.select)))
+        pages.append(prepared_queries[i].page_from_rows(rows, subselect_result))
     return pages
 
 

From 1b9133b767ecba64fb733d27e6669c756dd49597 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 14:02:03 -0700
Subject: [PATCH 62/64] flake8

---
 sqlakeyset/paging.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index b3dddb65..4313ed07 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -24,7 +24,7 @@
 from sqlalchemy.engine.interfaces import Dialect
 from sqlalchemy.orm import Session
 from sqlalchemy.orm.query import Query
-from sqlalchemy.sql.expression import ColumnElement, literal
+from sqlalchemy.sql.expression import ColumnElement, literal, union_all
 from sqlalchemy.sql.selectable import Select
 
 from .columns import OC, MappedOrderColumn, find_order_key, parse_ob_clause

From 1909b8e9e29d25896f6742b242f8a384976d5f72 Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 14:11:40 -0700
Subject: [PATCH 63/64] Clean up single query select.

---
 sqlakeyset/paging.py | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index 4313ed07..d5d77043 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -538,10 +538,12 @@ def select_homogeneous_pages(
 
     prepared_queries = [_core_prepare_homogeneous_page(request, s, i) for i, request in enumerate(requests)]
 
-    select = union_all(
-        *[p.paging_query.select for p in prepared_queries]
-    )
-    if len(prepared_queries) > 1:
+    if len(requests) == 1:
+        select = prepared_queries[0].paging_query.select
+    else:
+        select = union_all(
+            *[p.paging_query.select for p in prepared_queries]
+        )
         select = select.order_by(text("_page_identifier"), text("_row_number"))
 
     print(f"Select statement: {select}")

From 1af24f8d8c57121b6d0280ed4d22894098c20feb Mon Sep 17 00:00:00 2001
From: Matthew Albrecht <matt@delfina.com>
Date: Tue, 18 Jul 2023 14:38:34 -0700
Subject: [PATCH 64/64] Uncomment test to send Anthony error.

---
 sqlakeyset/paging.py | 2 +-
 tests/test_paging.py | 2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/sqlakeyset/paging.py b/sqlakeyset/paging.py
index d5d77043..85ba6ab8 100644
--- a/sqlakeyset/paging.py
+++ b/sqlakeyset/paging.py
@@ -558,7 +558,7 @@ def select_homogeneous_pages(
         page_to_rows[row._page_identifier].append(row)
 
     pages = []
-    # This is an unfortunate side effect of union_all. It appears we union_all
+    # This is an unfortunate side effect of union_all. It appears when we union_all
     # a bunch of selects, it changes the "keys" on us in cases where the column
     # name and python attribute don't match. So we have to execute the first
     # query standalone to ge the correct keys.
diff --git a/tests/test_paging.py b/tests/test_paging.py
index e206a71e..85c3ecd9 100644
--- a/tests/test_paging.py
+++ b/tests/test_paging.py
@@ -504,7 +504,6 @@ def test_orm_multiple_pages_empty_queries():
     assert get_homogeneous_pages([]) == []
 
 
-"""
 def test_core_multiple_pages(no_sqlite_dburl):
     with S(no_sqlite_dburl, echo=ECHO) as s:
         qs = [
@@ -513,7 +512,6 @@ def test_core_multiple_pages(no_sqlite_dburl):
             select(Book).order_by(Book.name, Book.id.desc()),
         ]
         check_multiple_paging_core(qs=qs, s=s)
-"""
 
 
 def test_core_multiple_pages_select_columns(no_sqlite_dburl):