AJAX请求：状态500 - ReadyState 4

I want to do some modifications on a table with AJAX.

In localhost all is allright but after transfer on production server, 500 Error.

I saw on other topics the problem should be on my .php or with my Apache server.

It's my first time that I use AJAX then I'm not comfortable with this technology.

For example, I want to delete an offer with the Delete button.

My .js :

//Action supprimer
$(".suppr").on("click", function(e){
    e.preventDefault();
    var conf=confirm("Cette offre sera supprimée, valider ?");

    if(conf==true){
        var id_promo=$(this).parent().parent().attr('id');
        console.log(id_promo);
        var ligne=$(this).parent().parent();
        var data="op=suppr&id_promo="+id_promo;
        var td=($(this).parent());

        td.html(ajax_loader);



        var request=$.ajax({
            url:"ajax_promo.php",
            method:"POST",
            data:data                
        });

        request.done(function(){
           console.log(request);
           ligne.empty(); 
        });

        request.fail(function(){
            console.log(request);

            console.log("Fail AJAX");
        });


    }

});

My .php

/************************ Action bouton "Supprimer" ***************************/

if($_POST["op"]=="suppr" && !empty($_POST['id_promo'])){
       $query="UPDATE professionnel_promo"
               . " SET online=2"
               . " WHERE id=".$_POST['id_promo'];

    if(sql_query($query)){
        echo "Delete OK";
    }
    else{
        echo "Fail Delete";
    }

}

Thanks for help :)

I would rewrite

 var data="op=suppr&id_promo="+id_promo;

with:

 var data='{op: "suppr", id_promo : "' + id_promo '"}';

Simply because the former is passed throught _GET superglobal, the latter with _POST

Solved problem ! It was a problem with SQL connection, I just changed permissions and it's ok.

Ty for all your replies :)