$db->query("SELECT company.c_name, recruiter.r_email, job.j_name, job.j_exp FROM recruiter INNER JOIN company ON recruiter.c_id = company.c_id INNER JOIN job ON recruiter.r_id=job.r_id WHERE job.j_name IN ('". implode("','", $_POST['select1']). "') AND job.j_exp IN ('". implode("','", $_POST['select2']). "') AND company.c_name like'".$_POST['txt']."%'");
if($db->db_num()>0){
echo json_encode($db->fetch_assoc());
}else{
echo "[]";
}