Fixed bug when attempting to execute an empty statement (#525).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -22,6 +22,9 @@ Thin Mode Changes
 Thick Mode Changes
 ++++++++++++++++++
 
+#)  Executed statements are normalized by removing leading and trailing spaces
+    before being sent to Oracle Database.
+
 Common Changes
 ++++++++++++++
 
@@ -32,6 +35,8 @@ Common Changes
     :attr:`oracledb.defaults.fetch_lobs <Defaults.fetch_lobs>` and
     :attr:`oracledb.defaults.fetch_decimals <Defaults.fetch_decimals>` are now
     stored with the operation and used during pipeline execution.
+#)  Fixed bug when attempting to execute an empty statement
+    (`issue 525 <https://github.com/oracle/python-oracledb/issues/525>`__).
 #)  API documentation is now generated from the source code.
 
 

src/oracledb/cursor.py

@@ -126,6 +126,17 @@ def _call_get_execute_args(
         statement = "".join(statement_parts)
         return (statement, bind_values)
 
+    def _normalize_statement(self, statement: Optional[str]) -> Optional[str]:
+        """
+        Normalizes a statement by stripping leading and trailing spaces. If the
+        result is an empty string, an error is raised immediately.
+        """
+        if statement is not None:
+            statement = statement.strip()
+            if not statement:
+                errors._raise_err(errors.ERR_EMPTY_STATEMENT)
+        return statement
+
     def _prepare(
         self, statement: str, tag: str = None, cache_statement: bool = True
     ) -> None:
@@ -142,7 +153,10 @@ def _prepare_for_execute(
         """
         self._verify_open()
         self._impl._prepare_for_execute(
-            self, statement, parameters, keyword_parameters
+            self,
+            self._normalize_statement(statement),
+            parameters,
+            keyword_parameters,
         )
 
     def _verify_fetch(self) -> None:
@@ -891,7 +905,7 @@ def executemany(
         """
         self._verify_open()
         num_execs = self._impl._prepare_for_executemany(
-            self, statement, parameters
+            self, self._normalize_statement(statement), parameters
         )
         self._impl.suspend_on_success = suspend_on_success
         if num_execs > 0:
@@ -1227,7 +1241,7 @@ async def executemany(
         """
         self._verify_open()
         num_execs = self._impl._prepare_for_executemany(
-            self, statement, parameters
+            self, self._normalize_statement(statement), parameters
         )
         self._impl.suspend_on_success = suspend_on_success
         if num_execs > 0:

src/oracledb/errors.py

@@ -289,6 +289,7 @@ def _raise_not_supported(feature: str) -> None:
 ERR_SCROLL_OUT_OF_RESULT_SET = 2063
 ERR_POOL_MAX_LESS_THAN_MIN = 2064
 ERR_ARROW_SPARSE_VECTOR_NOT_ALLOWED = 2065
+ERR_EMPTY_STATEMENT = 2066
 
 # error numbers that result in NotSupportedError
 ERR_TIME_NOT_SUPPORTED = 3000
@@ -587,6 +588,7 @@ def _raise_not_supported(feature: str) -> None:
     ERR_DUPLICATED_PARAMETER: (
         '"{deprecated_name}" and "{new_name}" cannot be specified together'
     ),
+    ERR_EMPTY_STATEMENT: ("an empty statement cannot be executed"),
     ERR_EXCEEDED_IDLE_TIME: (
         "the database closed the connection because the connection's idle "
         "time has been exceeded"

src/oracledb/impl/thin/cursor.pyx

@@ -169,7 +169,7 @@ cdef class BaseThinCursorImpl(BaseCursorImpl):
         if self._statement is not None:
             self._conn_impl._return_statement(self._statement)
             self._statement = None
-        self._statement = self._conn_impl._get_statement(statement.strip(),
+        self._statement = self._conn_impl._get_statement(statement,
                                                          cache_statement)
         self.fetch_metadata = self._statement._fetch_metadata
         self.fetch_vars = self._statement._fetch_vars

tests/test_3900_cursor_execute.py

@@ -562,6 +562,13 @@ def test_3935(self):
         with self.assertRaisesFullCode("ORA-01403"):
             self.cursor.execute("begin raise no_data_found; end;")
 
+    def test_3936(self):
+        "3936 - test executing an empty statement"
+        with self.assertRaisesFullCode("DPY-2066"):
+            self.cursor.execute("")
+        with self.assertRaisesFullCode("DPY-2066"):
+            self.cursor.execute("  ")
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()

tests/test_4000_cursor_executemany.py

@@ -441,6 +441,13 @@ def test_4028(self):
         "4028 - test executemany with empty parameter set"
         self.cursor.executemany("insert into TestTempTable values (:1)", [])
 
+    def test_4029(self):
+        "4029 - test executemany with an empty statement"
+        with self.assertRaisesFullCode("DPY-2066"):
+            self.cursor.executemany("", 5)
+        with self.assertRaisesFullCode("DPY-2066"):
+            self.cursor.executemany("  ", 5)
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()

tests/test_5400_cursor_execute_async.py

@@ -593,6 +593,13 @@ async def test_5436(self):
         with self.assertRaisesFullCode("ORA-01403"):
             await self.cursor.execute("begin raise no_data_found; end;")
 
+    async def test_5437(self):
+        "5437 - test executing an empty statement"
+        with self.assertRaisesFullCode("DPY-2066"):
+            await self.cursor.execute("")
+        with self.assertRaisesFullCode("DPY-2066"):
+            await self.cursor.execute("  ")
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()

tests/test_6100_cursor_executemany_async.py

@@ -380,6 +380,13 @@ async def test_6124(self):
         sql = "insert into TestTempTable values (:1)"
         await self.cursor.executemany(sql, [])
 
+    async def test_6125(self):
+        "6125 - test executemany with an empty statement"
+        with self.assertRaisesFullCode("DPY-2066"):
+            await self.cursor.executemany("", 5)
+        with self.assertRaisesFullCode("DPY-2066"):
+            await self.cursor.executemany("  ", 5)
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()