Fixed bug when a query is re-executed with the setting

"oracledb.defaults.fetch_lobs = False" after a table underlying the
query is dropped and recreated.

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -15,6 +15,9 @@ Thin Mode Changes
 
 #)  Fixed bug when SQL is executed after first being parsed with Oracle
     Database 23c.
+#)  Fixed bug when a query is re-executed with the setting
+    ``oracledb.defaults.fetch_lobs = False`` after a table underlying the query
+    is dropped and recreated.
 #)  Fixed bug when warning message is encountered during connect
     (`issue 171 <https://github.com/oracle/python-oracledb/issues/171>`__).
 

src/oracledb/impl/thin/cursor.pyx

@@ -1,5 +1,5 @@
 #------------------------------------------------------------------------------
-# Copyright (c) 2020, 2022, Oracle and/or its affiliates.
+# Copyright (c) 2020, 2023, Oracle and/or its affiliates.
 #
 # This software is dual-licensed to you under the Universal Permissive License
 # (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
@@ -96,6 +96,7 @@ cdef class ThinCursorImpl(BaseCursorImpl):
             if typ_impl.is_xml_type:
                 var_impl.outconverter = \
                         lambda v: v if isinstance(v, str) else v.read()
+        self._statement._always_full_execute = self._statement._requires_define
 
     cdef int _fetch_rows(self, object cursor) except -1:
         """

src/oracledb/impl/thin/messages.pyx

@@ -2000,8 +2000,11 @@ cdef class ExecuteMessage(MessageWithData):
         """
         cdef:
             Statement stmt = self.cursor_impl._statement
-        if stmt._cursor_id != 0 and not stmt._requires_full_execute \
-                and not self.parse_only and not stmt._is_ddl \
+        if stmt._cursor_id != 0 \
+                and not stmt._requires_full_execute \
+                and not stmt._always_full_execute \
+                and not self.parse_only \
+                and not stmt._is_ddl \
                 and not self.batcherrors:
             if stmt._is_query and not stmt._requires_define \
                     and self.cursor_impl.prefetchrows > 0:

src/oracledb/impl/thin/statement.pyx

@@ -88,6 +88,7 @@ cdef class Statement:
         object _last_output_type_handler
         uint32_t _num_columns
         bint _requires_full_execute
+        bint _always_full_execute
         bint _requires_define
         bint _return_to_cache
         bint _in_use

tests/test_4300_cursor_other.py

@@ -913,5 +913,37 @@ def test_4369_bind_order_for_plsql(self):
             fetched_rows = self.cursor.fetchall()
             self.assertEqual(fetched_rows, rows)
 
+    def test_4370_rebuild_table_with_lob_in_cached_query(self):
+        "4370 - test rebuild of table with LOB in cached query"
+        table_name = "test_4370"
+        drop_sql = f"drop table {table_name} purge"
+        create_sql = f"""
+            create table {table_name} (
+                Col1 number(9) not null,
+                Col2 clob not null
+            )"""
+        insert_sql = f"insert into {table_name} values (:1, :2)"
+        query_sql = f"select * from {table_name} order by Col1"
+        data = [
+            (1, "CLOB value 1"),
+            (2, "CLOB value 2")
+        ]
+        try:
+            self.cursor.execute(drop_sql)
+        except:
+            pass
+        with test_env.FetchLobsContextManager(False):
+            self.cursor.execute(create_sql)
+            self.cursor.executemany(insert_sql, data)
+            self.cursor.execute(query_sql)
+            self.assertEqual(self.cursor.fetchall(), data)
+            self.cursor.execute(query_sql)
+            self.assertEqual(self.cursor.fetchall(), data)
+            self.cursor.execute(drop_sql)
+            self.cursor.execute(create_sql)
+            self.cursor.executemany(insert_sql, data)
+            self.cursor.execute(query_sql)
+            self.assertEqual(self.cursor.fetchall(), data)
+
 if __name__ == "__main__":
     test_env.run_test_cases()