php/mysql insert into query returns null -

i struggling project want read sql file formatted in specific way , execute queries in it. need check if first query has been executed in order continue. first query returns null value. can me please ? tried mysql error returns nothing too. here code.

<?php      $inserts = file_get_contents($nom_definitif);     $inserts = preg_replace('/--+\s.*/i', "", $inserts);     $inserts = preg_split("/;/si", $inserts);      $insert = str_replace('insert into', '', $inserts[0] . " ;");     $res_insert_etab = phpadm_dbquery('insert ' . $insert);      //this returns name of database     echo "db ".$phpadm_config['dbname_etablissements']."<br>";     //but returns null     echo "res_insert: ".$res_insert_etab."<br>";      if($res_insert_etab){         //get last inserted id         $last_etab_id = phpadm_dbinsertid();         //execute create database query         $create_query = str_replace('###_###etablissement_###_###', 'etablissement_'.$last_etab_id, $inserts[1]. " ;");              mysql_db_query($phpadm_config['dbname_etablissements'],$create_query);          echo "lastid ".$last_etab_id;         //$inserts = preg_replace($inserts[0], "", $inserts);          $i=0;         foreach ($inserts $insert) {             // 2 premières instructions exéctuées au dessus             if($i>1){                                $insert = str_replace('insert into', '', $insert);                 if(strlen($insert)>strlen('insert into')){                     $insert = str_replace('###_###etablissement_###_###', 'etablissement_'.$last_etab_id, $insert. " ;");                     $res_insertion = phpadm_dbquery('insert ' . $insert);                     echo "res".$res_insertion." <br>";                 }             }             $i++;         }     }