Stopping Duplicate Inserts

[justlukeyou]

Hi,

I am trying to come up with a way of stopping duplicate inserts from being into a table. I have got this point which creates an error message for duplicate follows but I am stuck on what to try next. Any suggestions please?

 

As far as I can tell I need something in the insert code that says if the value is already in the table it cannot be re-inserted and then echo the message.

 

 

 

$query = "INSERT INTO `follow` (`user_id`, `follow_user_id`) VALUES ('{$profileid}', '{$followerid}')";

$result = mysql_query($query);



    if (!$result){

    $errors[] = "Query: {$query}<br>Error: " . mysql_error();

    }

}



if(($profileid) == ($followerid)) {

$errors['sameprofile'] = "You cannot follow your own profile.";

}



$loginprofile = intval($_SESSION['userID']);



$query_rsSearch = "SELECT * FROM follow WHERE `follow_user_id` = '$loginprofile'";

$rsSearch = mysql_query($query_rsSearch) or die(mysql_error());

$row_rsSearch = mysql_fetch_assoc($rsSearch);

$totalRows_rsSearch = mysql_num_rows($rsSearch);



$duplicate = $profileid;





if(($loginprofile) == $row_rsSearch['follow_user_id']) {

$errors['duplicatefollow'] = "You already follow this profile.";

}

 

I have this across a number of pages so I should be able to re-use it quite often.

[justlukeyou]

Hi,

 

I have added this which returns the error message however I cant work out how to stop the duplicate input.  Can anyone who knows PHP able to advise how to stop the PHP insert once the error message runs?

 

 

    $query = mysql_query("SELECT * FROM follow WHERE follow_user_id  = '". $followerid ."'");
$duplicatefollow = null;
if (mysql_num_rows($query) > 0)
{
$duplicatefollow = 'You Already Follow This Profile.</a>.';
}   

 
if(isset($_POST['followbutton'])) {


$query = "INSERT INTO `follow` (`user_id`, `follow_user_id`) VALUES ('{$profileid}', '{$followerid}')";
$result = mysql_query($query);


    if (!$result){
    $errors[] = "Query: {$query}<br>Error: " . mysql_error();
    }
}