Question

I’m making a button which deletes an record from a mysql database.

I have made a database with 3 tables, 1: user, 2: activity, 3:user_activity.
In the user_activity you can find the UserID (from user) and ActivityID (from activity).

I have alreade made a script that can add both UserID and ActivityID to the user_activity table. But now i also want a button that remove that “row”.

so i made this javascript code with an onclick function:

$(".deleteActivity").click( function() {

    var user_activityId = $(this).data('activity');

    $.ajax({
        type: "POST",
        url: "delete_activity.php",
        data: {
            activity: user_activityId
        },
        dataType: 'json',
        success: function (data) {          
        }
    });
    $(this).hide(); 
});

And I made this delete_activity.php file:

<?php
  include "connection.php";

  $sql = "SELECT * FROM user WHERE Username = '".$_SESSION['Username']."' ";
  $stm = $db->prepare($sql);
  $result = $stm->execute(array());
  while($row = $stm->fetch(PDO::FETCH_ASSOC)) {
  $userID = $row['UserID'];
  echo $userID;
}

  $sql = "SELECT * FROM user_activity WHERE UserID = '".$userID."' ";
  $stm = $db->prepare($sql);
  $result = $stm->execute(array());
  while($row = $stm->fetch(PDO::FETCH_ASSOC)) {
  echo $row['ActivityID'];
}
?>

And this is the button:

echo '<input type="button" class="deleteActivity"  value="Activiteit verwijderen" data-activity="' . $row['ActivityID'] . '">';

As you can see, don’t delete anything yet, i only “echo” the ID’s so I can see the ID’s and check if those are the right ones.

I want to get the ActivityID from the “activity” on which I puch the button. With this ActivityID an can finish my query:

$sql = "SELECT * FROM user_activity WHERE UserID = '".$userID."' AND ActivityID = ??? ";

I hope everything is clear and that there is someone that can help me.

Answer 1

Use your posted user_activity_id on your query 😀 I don’t know the column name of your user_activity_id, so edit it in your case.

$userActivityId = filter_input(INPUT_POST, "activity");

$sql = "SELECT * FROM user_activity WHERE UserActivityId = :id";
$stm = $db->prepare($sql);
$stm->bindValue( ":id", $userActivityId, PDO::PARAM_INT);
if($stm->execute())
{
    $rows = $stm->fetchAll();
    foreach($rows as $row)
    {
         echo $row['ActivityId'];
         break;
    }
}