Fixed bug with re-execution of SQL that requires a define, such as

occurs when setting oracledb.defaults.fetch_lobs to the value False
(#41).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -20,6 +20,9 @@ Thin Mode Changes
     (`issue 26 <https://github.com/oracle/python-oracledb/issues/26>`__).
 #)  Fixed bug with handling of redirect data returned by some SCAN listeners
     (`issue 39 <https://github.com/oracle/python-oracledb/issues/39>`__).
+#)  Fixed bug with re-execution of SQL that requires a define, such as occurs
+    when setting `oracledb.defaults.fetch_lobs` to the value `False`
+    (`issue 41 <https://github.com/oracle/python-oracledb/issues/41>`__).
 
 Common Changes
 ++++++++++++++

src/oracledb/impl/thin/messages.pyx

@@ -1657,13 +1657,18 @@ cdef class ExecuteMessage(MessageWithData):
         Runs after the database response has been processed. If the statement
         executed requires define and is not a REF cursor (which would already
         have performed the define during its execute), then mark the message as
-        needing to be resent.
+        needing to be resent. If this is after the second time the message has
+        been sent, mark the statement as no longer needing a define (since this
+        only needs to happen once).
         """
         MessageWithData._postprocess(self)
         cdef Statement stmt = self.cursor_impl._statement
         if stmt._requires_define and stmt._sql is not None:
-            stmt._requires_full_execute = True
-            self.resend = True
+            if self.resend:
+                stmt._requires_define = False
+            else:
+                stmt._requires_full_execute = True
+                self.resend = True
 
     cdef int _write_execute_message(self, WriteBuffer buf) except -1:
         """

tests/test_4300_cursor_other.py

@@ -784,5 +784,23 @@ def test_4361_rowcount_after_close(self):
             self.assertEqual(cursor.rowcount, 1)
         self.assertEqual(cursor.rowcount, -1)
 
+    def test_4362_change_of_bind_type_with_define(self):
+        "4362 - changing bind type with define needed"
+        self.cursor.execute("truncate table TestClobs")
+        row_for_1 = (1, "Short value 1")
+        row_for_56 = (56, "Short value 56")
+        for data in (row_for_1, row_for_56):
+            self.cursor.execute("""
+                    insert into TestClobs (IntCol, ClobCol)
+                    values (:1, :2)""", data)
+        sql = "select IntCol, ClobCol from TestClobs where IntCol = :int_col"
+        with test_env.FetchLobsContextManager(False):
+            self.cursor.execute(sql, int_col="1")
+            self.assertEqual(self.cursor.fetchone(), row_for_1)
+            self.cursor.execute(sql, int_col="56")
+            self.assertEqual(self.cursor.fetchone(), row_for_56)
+            self.cursor.execute(sql, int_col=1)
+            self.assertEqual(self.cursor.fetchone(), row_for_1)
+
 if __name__ == "__main__":
     test_env.run_test_cases()