How can i check that it is the last record?

[colap]

<script type=text/javascript src="jquery-1.11.3.js"></script>
<input type="button" id="id_load_more" name="nm_load_more" value="Load More" />
<script type="text/javascript">
    $(document).ready(function() {
        var limit = 1;   
        console.log("ready!");   
        $( "input#id_load_more" ).on( "click", function( event ) {
              //event.stopPropagation();   
            $.ajax({
                method: "POST",
                url: "load_more.php",
                data: {"page": limit},
                dataType: "JSON",
                success: function(data) {
                    console.log(data);
                    //console.log(data.status);
                    limit++;
                }
            });
       
        });
    });
</script>

If there is no data in table limit++ needs not to increment. How can i do it?

This is the load_more.php

<?php

if (session_id() == '') {
    session_start();
}

require_once ('./functions.php');

$dbh = mysql_connection();
$user_id = $_SESSION['login_user_id'];

$sql_total_rows = "SELECT u.id, u.username as non_friend
FROM users u
LEFT JOIN
    (
        SELECT user_id, friend_id
        FROM friends
        WHERE user_id = $user_id

            UNION

        SELECT friend_id, user_id
        FROM friends
        WHERE friend_id = $user_id
       
    ) f  ON u.id = f.friend_id
WHERE u.id <> $user_id
     AND f.friend_id IS NULL
ORDER BY id";
$stmt_total_rows = $dbh->prepare($sql_total_rows);
$stmt_total_rows->execute();
$result_total_rows = $stmt_total_rows->rowCount();
//echo $result_total_rows;

$number_of_items_per_page = 2;
$total_number_of_page = ceil($result_total_rows/$number_of_items_per_page);
//echo $total_number_of_page;

//$page = $_POST['page'];
//$_POST['page'] = 2;
$limit = ($_POST['page'] - 1) * $number_of_items_per_page;

$sql_non_friends = "SELECT u.id, u.username as non_friend
FROM users u
LEFT JOIN
    (
        SELECT user_id, friend_id
        FROM friends
        WHERE user_id = $user_id

            UNION

        SELECT friend_id, user_id
        FROM friends
        WHERE friend_id = $user_id
       
    ) f  ON u.id = f.friend_id
WHERE u.id <> $user_id
     AND f.friend_id IS NULL
ORDER BY id limit $limit , $number_of_items_per_page;";

//echo $sql_non_friends;

$stmt = $dbh->prepare($sql_non_friends);
$stmt->execute();
$result = $stmt->fetchAll();
//formatted_value($result);

/*
foreach ($result as $value) {
    //formatted_value($value);
    $user_id = $value['id'];
    echo $value['non_friend'];
    echo "<a href='add_friend.php?user_id=$user_id' >Add Friend</a>";
    echo '<br/>';
}
*/
//echo $_POST;
//echo json_encode($_POST);
if($_POST['page'] = $total_number_of_page) {
    $data['status'] = 1;
    $data['result'] = $result;
    echo json_encode($data);
} else {
    echo json_encode($result);
}

It is a ajax request to do load more data after clicking the button.

Thanks in advance.

Edited August 29, 2015 by Ch0cu3r

[Ch0cu3r]

1.  $dbh->prepare()  is for initializing a prepared statement. For each values used in the query you should be calling bindParam

 

2. Have your php script to not output the result if we are on the last page. In your javascript code you will only increment limit when data is not empty

// only output the result if we are not on the last page
if($_POST['page'] != $total_number_of_page)
{
    echo json_encode($result);
}

In your javascript

                success: function(data) {
                    // data is not empty, increment limit
                    if(data.length != 0) {
                        limit++;
                    }
                }

[CroNiX]

Since this is a comparison, you need to use double == here instead of assigning the value:

if($_POST['page'] = $total_number_of_page) {

[colap]

 

1.  $dbh->prepare()  is for initializing a prepared statement. For each values used in the query you should be calling bindParam

 

2. Have your php script to not output the result if we are on the last page. In your javascript code you will only increment limit when data is not empty

// only output the result if we are not on the last page
if($_POST['page'] != $total_number_of_page)
{
    echo json_encode($result);
}

In your javascript

                success: function(data) {
                    // data is not empty, increment limit
                    if(data.length != 0) {
                        limit++;
                    }
                }

<input type="button" id="id_load_more" name="nm_load_more" value="Load More" />

If the data.length = 0 , then there will be no button. How can i do this?

[Ch0cu3r]

 

If the data.length = 0 , then there will be no button

Why would there be no button?

 

Is there more code that removes the button?

[colap]

Why would there be no button?

 

Is there more code that removes the button?

 

Button is not necessary if there is not more data.

No more code.

[Ch0cu3r]

Sorry misread your last post. To remove the button you should be able to do

                success: function(data) {
                    // data is not empty, increment limit
                    if(data.length != 0) {
                        limit++;
                    } else {
                        $(this).hide();
                    }
                }

[colap]

 

Sorry misread your last post. To remove the button you should be able to do

                success: function(data) {
                    // data is not empty, increment limit
                    if(data.length != 0) {
                        limit++;
                    } else {
                        $(this).hide();
                    }
                }

It hides the button, but there is one extra request from button to load data. How can i stop it? How can i let jquery know that it is the last record so hide the button?