使用Ajax将我的Javascript变量传递给PHP

Question

I am trying to take my Javascript variable and pass it to a PHP variable using AJAX so I can update my SQL. Currently the function is being called but AJAX is not sending the data to PHP.php.

CODE UPDATE:

function placeData(){
        //Variable is caled and input is updated//
        var hour1Data = document.getElementById("hourDataInput").value;
        document.getElementById("hour1").innerHTML = hour1Data;

        //Launch AJAX//
        $.ajax({
            type: "POST",
            url: "PHP.php",
            data: {hour1Data: "hello", loginName: <?php echo $_POST['loginName'] ?>},
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function(result){
                alert(result.d);
                console.log(result);
            }
        });
    }

//php.php

 if(isset($_POST['hour1Data']))
        {   
            echo "something is working"; 
            print_r($_POST); //Check the values here first
            $hour1Data = $_POST['hour1Data'];
            $sql = "UPDATE `$user` SET `$dateName`='$hour1Data' WHERE hour=1";
            if ($conn->query($sql) === TRUE) {
            echo "Record updated successfully";
            }
            else {
                echo "problem adding value";
            }
        }

Answer 1

Here is the code:

$.ajax({
    type: "POST",
    url: "PHP.php", //Check the url 
    data: {hour1Data: 1, loginName: "testUser"},
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function(result){
        alert(result.d);
        console.log(result);
    }
});

Php code:

 if(isset($_POST['hour1Data']))
            {   
                echo "<pre>"; 
                print_r($_POST); //Check the values here first
                $hour1Data = $_POST['hour1Data'];
                $sql = "UPDATE `$user` SET `$dateName`='$hour1Data' WHERE hour=1";
                if ($conn->query($sql) === TRUE) {
                echo "Record updated successfully";
                }
                else {
                    echo "problem adding value";
                }
            }

Answer 2

Remove contentType as $_POST is for form-encoded content types. You can look at this posted problem here for some reference -

Ajax call with contentType: 'application/json' not working .

It is also important to note what type of data you are expecting in your Ajax request and the data type returned by your PHP file. Put error callback so you will know what's the error response.

Hope that helps.