我有搜索表单。在这里多个领域。有时我会提交一个字段，有时提交两个字段值，有时提交多个字段值。if(isset($_POST['search'])){$projectName=$_POST['pName'];$clientId=$_POST['s_by_clientName'];$departmentId=$_POST['s_by_department'];$statusName=$_POST['s_by_status'];if(!empty($projectName)){$searchSql=mysql_query("select*fromproject_listwhereprojec