select SUM(ba.balance_days) from kqgl_asso_leave_balance ba where ba.userid = #{userid} and ba.org_code = #{orgcode} and ba.leave_rules_id = #{leaverulesid}
select COALESCE(SUM(ba.balance_days), 0) AS total_balance from kqgl_asso_leave_balance ba where ba.userid = #{userid} and ba.org_code = #{orgcode} and ba.leave_rules_id = #{leaverulesid}