Added support for str objects for bit type with SQLAlchemy - #137

Co-authored-by: Giacomo rua <giacomo.rua@outlook.com>

Author: ankane

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.4.2 (unreleased)
+
+- Added support for `str` objects for `bit` type with SQLAlchemy
+
 ## 0.4.1 (2025-04-26)
 
 - Fixed `SparseVector` constructor for SciPy sparse matrices

pgvector/sqlalchemy/bit.py

@@ -14,6 +14,18 @@ def get_col_spec(self, **kw):
             return 'BIT'
         return 'BIT(%d)' % self.length
 
+    def bind_processor(self, dialect):
+        if dialect.__class__.__name__ == 'PGDialect_asyncpg':
+            import asyncpg
+
+            def process(value):
+                if isinstance(value, str):
+                    return asyncpg.BitString(value)
+                return value
+            return process
+        else:
+            return super().bind_processor(dialect)
+
     class comparator_factory(UserDefinedType.Comparator):
         def hamming_distance(self, other):
             return self.op('<~>', return_type=Float)(other)

tests/test_sqlalchemy.py

@@ -596,6 +596,11 @@ async def test_bit(self, engine):
                 item = await session.get(Item, 1)
                 assert item.binary_embedding == embedding
 
+                if engine == asyncpg_engine:
+                    session.add(Item(id=2, binary_embedding='101'))
+                    item = await session.get(Item, 2)
+                    assert item.binary_embedding == embedding
+
         await engine.dispose()
 
     @pytest.mark.asyncio