Erreur SQL

$reponse5 = mysql_query("SELECT * FROM construction_unite") or die(mysql_error()); 
    
  while ($donnees5 = mysql_fetch_array($reponse5)) 
    { 
     $reponse5_1 = mysql_query("SELECT * FROM qgjoueur WHERE pseudo = '".$donnees5['pseudo']."'") or die(mysql_error()); 
     $donnees5_1 = mysql_fetch_array($reponse5_1); 
     $reponse5_2 = mysql_query("SELECT nom2 FROM fleet WHERE id = '".$donnees5['categorie']."'") or die(mysql_error()); 
     $donnees5_2 = mysql_fetch_array($reponse5_2); 
      
     $rien =$donnees5_2['nom2']; 
     $rien2=$donnees5['nbreenplus']; 
     $newun =$donnees5['nbreenplus'] + $donnees5_1[''.$rien.'']; 
      
      
      if ($dts >= $donnees5['timestampfin']) 
       {  
  
        mysql_query("UPDATE qgjoueur SET ".$rien."='$newun' WHERE pseudo='$pseudo'")or die (mysql_error()); 
        mysql_query("DELETE FROM construction_unite WHERE pseudo = '$pseudo' AND  nbreenplus = '$rien2' AND categorie = '$cate'")or die(mysql_error());       
  
       } 
    }