dblayeroo: push the group_concat_max_len to maximum allowed

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@3820 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

dblayeroo.php

@@ -147,6 +147,16 @@ class dblayeroo
       $this->sep = "`";
       if ($this->databasename () === null)
         $this->DBException ("No Database provided in DSN");
+      // Force the GROUP_CONCAT value max to the max allowed from the server
+      $st = self::$instance[$this->dsn]->query (
+        "SHOW VARIABLES LIKE 'max_allowed_packet'", PDO::FETCH_COLUMN, 1);
+      $rows = $st->fetchAll ();
+      if (! isset ($rows[0]))
+        throw new \Exception (
+          "Can't read the max_allowed_packet from the MySQL server", 500);
+      $max_allowed_packet = $rows[0];
+      self::$instance[$this->dsn]->exec (
+        "SET SESSION group_concat_max_len = $max_allowed_packet");
       break;
     case "pgsql":
       if (! array_key_exists ($this->dsn, self::$instance))