我有 20 个表,我想通过比较数据来获取记录。
这些表有超过 5000 条记录。
现在的问题是数据获取非常慢并且生成一个错误而不是显示数据
致命错误:超过 30 秒的最大执行时间
那是在 PHP 中,查询是 "$query1 = "SELECT employees.*,upgradations.EmpID, upgradations.BPZ,picture.PicPath, designation.Designat FROM upgradations,employees,picture,designation
WHERE upgradations.Designationz=designation.Code AND upgradations.UPStatus=1 AND picture.EmpID=employees.EmpID AND upgradations.EmpID=employees.EmpID
AND employees.DEntry='$UCNIC' ORDER BY employees.ID ASC LIMIT $start, $limit ";"