JQuery Ajax调用PHP页面无法正常工作

I have seen many posts but still not able to figure out why this code is not working. I have a user_dashboard.html which contains the code:-

<script>
$(document).ready(function (e) {
    //e.preventDefault();

    $('#search_button').click( function() {
        $.get("db_test2.php", function(data, status) {
            console.log("Test Log");
            alert("Data:"+data+"
Status:"+status);
        });
    });
});
</script>

The db_test2.php is a file present in the same folder and contains the code:-

<?php
    echo "This is a db test";
?>

The problem is that I am not getting any alert and no console logs are being generated.

You have a submit button, so by default after running your click handler, it will submit the form immediately. To prevent this, you can return false or e.preventDefault():

$('#search_button').click( function() {
    $.get("db_test2.php", function(data, status) {
        console.log("Test Log");
        alert("Data:"+data+"
Status:"+status);
    });
    return false; // stop the form being submitted
});

Just to make sure, put a console.log("clicked"); to make sure the method is being called

$('#search_button').click( function() {
    console.log("clicked"); // here
    $.get("db_test2.php", function(data, status) {
        console.log("Test Log");
        alert("Data:"+data+"
Status:"+status);
    });
});

EDIT

Works fine on my JSFiddle

If db_test2.php is within the same directory as the file you're in, try putting the whole url

e.g. www.domain.co.uk/directory/db_test2.php

if it works then you know that is it not finding db_test2.php and that is where your issue is.

Also, are there any errors in your console?

I would insert the following alerts earlier in the code, to try and track the problem:

<script>
   $(document).ready(function (e) {

      alert('#search_button').length);//to confirm the presence of the button

      $('#search_button').click( function() {

      alert('Button clicked!');

      $.get("db_test2.php", function(data, status) {
        console.log("Test Log");
        alert("Data:"+data+"
Status:"+status);
});
});
});
</script>

So, apart from your "Test Log", I assume there's no other Javascript error on the console? And finally, reconfirm that your 'db_test2.php' is indeed where you thought it was, 'cause a 404 error can often cause this kind of silent, frustrating error!