วิธีแช็คค่าจากฐานข้อมูลว่าค่าที่รับมาเป็น insert or update ในรูปแแบบ multi insert

select count(id) from table where user='".$_POST['username']."' and pass='".$_POST['password']."';

select count(id) from table where user='".$_POST['username']."' ;

if(){
//updatre
    echo  population_id[$i]    //มันต้องเท่ากับ  987654321

}else{
//insert
   echo  population_id[$i]    //ต้องได้ค่าเป็น 123456789 ,4545454455

}

for($i=0;$i<=count($_POST['recode']);$i++){

                $population_id[$i] = $_POST['population_id'];
		$username[$i] = $_POST['username'];
		$password[$i] = $_POST['password'];


$sel =$con->prepare("SELECT count(population_id) FROM `member` WHERE `population_id` = '".$population_id[$i]."' ");
$sel->execute();
$num = $sel->rowCount();
if($num>0){
    
       echo  population_id[$i]
}else{

       echo  population_id[$i]
}



}

$mysql=new mysqli( 'localhost', 'test',test',test');
if($rs=$mysql->query( "insert into table set recode='newcode', user='blabla' ")){
  echo 'This statement can insert and insert_id=' , $mysql->insert_id;
}else{
   if($rs=$mysql->query("update table set recode='newcode' where user='blabla' ")){
      echo 'This statement is not error and affected_rows=', $mysql->affected_rows;
  }else echo $mysql->error;
}