fix: use single quotes in SQL query to support ANSI_QUOTES mode

[prathamesh04]

Description

This PR fixes two bugs in the MySQL Shell for VS Code plugin that cause connection failures when ANSI_QUOTES is enabled in sql_mode.

Bug 1: SQL Query Uses Double Quotes (Error 1054)

In DbMySQLSessionSetupTasks.py, the HeatWaveCheckTask.on_connected() method executes a SQL query to check if the sys.EXPLAIN_ERROR procedure is available. The query uses double quotes for string literals:

WHERE ROUTINE_SCHEMA="sys"
  AND ROUTINE_NAME="mle_explain_error"
  AND ROUTINE_TYPE="PROCEDURE"

When ANSI_QUOTES is enabled in sql_mode, MySQL interprets double-quoted values as identifiers (column names) rather than string literals, causing Error 1054: Unknown column 'sys' in 'where clause'.

Fix: Changed double quotes to single quotes:

WHERE ROUTINE_SCHEMA='sys'
  AND ROUTINE_NAME='mle_explain_error'
  AND ROUTINE_TYPE='PROCEDURE'

Bug 2: TypeError in Error Handling

When the above error occurs, DbSession.terminate_thread() calls self._message_callback("ERROR", self.thread_error). However, DbModuleSession.on_session_message() expects 3 positional arguments:

def on_session_message(self, type, message, result, request_id=None):

The result argument is not passed, causing:

TypeError: DbModuleSession.on_session_message() missing 1 required positional argument: 'result'

Fix: Added None as the result parameter:

self._message_callback("ERROR", self.thread_error, None)

Related Issue

Closes #88

Changes

• gui/backend/gui_plugin/core/dbms/DbMySQLSessionSetupTasks.py: Changed double quotes to single quotes in SQL query
• gui/backend/gui_plugin/core/dbms/DbSession.py: Added missing result parameter in terminate_thread()