How to trigger the "error" callback in JQuery AJAX call using in PHP

I have PHP code snippet the following:

if (!($result = mysql_query($query, $link))) {
   die("Invalid SQL query: " . $query);
}

And I have JQuery code snippet the following:

$.ajax({
        url: "....search.php", 
        data: ...,

        async: false, //to trigger error alert

        success: function(xml) {
            ...
        },

        error: function(xml) {
            foundError = true;
        },

        dataType: "xml"
    });

if(foundError) {
        setProgress("Could not complete the search because an error was found", ProgressBar.ERROR);
}

Is it开发者_开发技巧 possible to have the die call trigger JQuery error function callback? If not, how would I trigger it otherwise?

Try this:

if (!($result = mysql_query($query, $link))) {
   header("HTTP/1.1 404 Not Found");
}

Choose the error appropriate for your application

You cannot signal client-side code from the server (at least, not in the way you're expecting).

When using AJAX, best to use proper HTTP response codes and have jQuery act upon those in the error: callback.

You cannot access the ajax error like that as there was no ajax error. What you could do, is check your xml variable in the success section; if it starts with Invalid SQL query you know there was a php error.

To tidy things up, you probably want to return some more information (xml / json) in case of an error instead of just a string.