Fixed bug resulting in an exception when Cursor.executemany() is called

with bind variables and an empty parameter set (#508).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -44,6 +44,9 @@ Thin Mode Changes
     frame <dataframeformat>`.
 #)  Fixed bug using :ref:`Oracle Advanced Queuing <aqusermanual>` when
     attempting to dequeue using an invalid :attr:`DeqOptions.msgid`.
+#)  Fixed bug resulting in an exception when :meth:`Cursor.executemany()` is
+    called with SQL containing bind variables and an empty parameter set
+    (`issue 508 <https://github.com/oracle/python-oracledb/issues/508>`__).
 
 Thick Mode Changes
 ++++++++++++++++++

src/oracledb/cursor.py

@@ -755,9 +755,10 @@ def executemany(
         num_execs = self._impl._prepare_for_executemany(
             self, statement, parameters
         )
-        self._impl.executemany(
-            self, num_execs, bool(batcherrors), bool(arraydmlrowcounts)
-        )
+        if num_execs > 0:
+            self._impl.executemany(
+                self, num_execs, bool(batcherrors), bool(arraydmlrowcounts)
+            )
 
     def fetchall(self) -> list:
         """
@@ -1007,9 +1008,10 @@ async def executemany(
         num_execs = self._impl._prepare_for_executemany(
             self, statement, parameters
         )
-        await self._impl.executemany(
-            self, num_execs, bool(batcherrors), bool(arraydmlrowcounts)
-        )
+        if num_execs > 0:
+            await self._impl.executemany(
+                self, num_execs, bool(batcherrors), bool(arraydmlrowcounts)
+            )
 
     async def fetchall(self) -> list:
         """

src/oracledb/impl/thick/cursor.pyx

@@ -346,22 +346,21 @@ cdef class ThickCursorImpl(BaseCursorImpl):
         if self.bind_vars is not None:
             self._perform_binds(cursor.connection, num_execs_int)
 
-        if num_execs_int > 0:
-            with nogil:
-                status = dpiStmt_executeMany(self._handle, mode, num_execs_int)
-                dpiContext_getError(driver_info.context, &error_info)
-                dpiStmt_getRowCount(self._handle, &rowcount)
-            if not self._stmt_info.isPLSQL:
-                self.rowcount = rowcount
-            if status < 0:
-                error = _create_new_from_info(&error_info)
-                if self._stmt_info.isPLSQL and error_info.offset == 0:
-                    error.offset = rowcount
-                raise error.exc_type(error)
-            elif error_info.isWarning:
-                self.warning = _create_new_from_info(&error_info)
-            if self._stmt_info.isReturning or self._stmt_info.isPLSQL:
-                self._transform_binds()
+        with nogil:
+            status = dpiStmt_executeMany(self._handle, mode, num_execs_int)
+            dpiContext_getError(driver_info.context, &error_info)
+            dpiStmt_getRowCount(self._handle, &rowcount)
+        if not self._stmt_info.isPLSQL:
+            self.rowcount = rowcount
+        if status < 0:
+            error = _create_new_from_info(&error_info)
+            if self._stmt_info.isPLSQL and error_info.offset == 0:
+                error.offset = rowcount
+            raise error.exc_type(error)
+        elif error_info.isWarning:
+            self.warning = _create_new_from_info(&error_info)
+        if self._stmt_info.isReturning or self._stmt_info.isPLSQL:
+            self._transform_binds()
 
     def get_array_dml_row_counts(self):
         """

tests/test_4000_cursor_executemany.py

@@ -437,6 +437,10 @@ def test_4027(self):
         with self.assertRaisesFullCode("DPY-2016"):
             self.cursor.executemany(None, 4)
 
+    def test_4028(self):
+        "4028 - test executemany with empty parameter set"
+        self.cursor.executemany("insert into TestTempTable values (:1)", [])
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()

tests/test_6100_cursor_executemany_async.py

@@ -378,6 +378,11 @@ async def test_6123(self):
         with self.assertRaisesFullCode("DPY-2001"):
             await cursor.executemany(None, [1, 2])
 
+    async def test_6124(self):
+        "6124 - test executemany with empty parameter set"
+        sql = "insert into TestTempTable values (:1)"
+        await self.cursor.executemany(sql, [])
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()