使用AJAX和PHP在无限滚动中获取表的结果？

Question

I'm trying to get 20 results from my table on the fly(when user scrolls to the bottom) using AJAX and PHP.

Ive the follwoing so far...

AJAX

// Infinite Scroll
loadData( 0 );
//Hide Loader for Infinite Scroll
$('div.ajaxloader').hide();

});

function loadData ( last_id ) {
    var $entries = $('.directory'),
        $loader = $('.ajaxloader', $entries).show();
    $.get( '/getentries.php', { last_id : last_id }, function( data ) {
        $entries.append( data ).append( $loader.hide() );
        filterEntries();
    });
};


//Isotope filter - no changes to this code so I didn't include it

$(window).scroll(function () {
    if ($(window).scrollTop() >= $(document).height() - $(window).height() - 10) {
        $('div.ajaxloader').show('slow');
        loadData( $( '.directory item:last' ).data('id') )
    }

PHP

try {
  // Connect and create the PDO object
  $conn = new PDO("mysql:host=$hostdb; dbname=$namedb", $userdb, $passdb);
  $conn->exec("SET CHARACTER SET utf8");      // Sets encoding UTF-8

  // Define and perform the SQL SELECT query
  $sql = "SELECT * FROM `directory` WHERE user_active != ``";
  $result = $conn->query($sql);

  $sth = $conn->prepare("SELECT * FROM directory WHERE user_active != ''");
        $sth->execute(array(':county' => $county));

        $c = 1;
        while ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
            echo '<div class="entry';
                 if (($c % 4) == 1) echo ' alpha ';
           // ECHO RESULT STYLES ETC HERE
        $c++;
        }

  $conn = null;        // Disconnect
}
catch(PDOException $e) {
  echo $e->getMessage();
}

Now my AJAX and query seem to work fine, the problem im having though is its just pulling asll of the records again, as opposed to the next 20?

Ive never done this before so sorry if i sound naive but any help would be much appreciated!

Answer 1

You need to add limit in your mysql query. please see the below code

// Infinite Scroll
loadData( 0 );
//Hide Loader for Infinite Scroll
$('div.ajaxloader').hide();

});

function loadData ( last_id ) {
    var $entries = $('.directory'),
        $loader = $('.ajaxloader', $entries).show();
    $.get( '/getentries.php?startp=0&endp=20', { last_id : last_id }, function( data ) {
        $entries.append( data ).append( $loader.hide() );
        filterEntries();
    });
};


//Isotope filter - no changes to this code so I didn't include it

$(window).scroll(function () {
    if ($(window).scrollTop() >= $(document).height() - $(window).height() - 10) {
        $('div.ajaxloader').show('slow');
        loadData( $( '.directory item:last' ).data('id') )
    }


PHP


try {
  // Connect and create the PDO object
  $conn = new PDO("mysql:host=$hostdb; dbname=$namedb", $userdb, $passdb);
  $conn->exec("SET CHARACTER SET utf8");      // Sets encoding UTF-8

  // Define and perform the SQL SELECT query
  $sql = "SELECT * FROM `directory` WHERE user_active != ``";
  $result = $conn->query($sql);

  $sth = $conn->prepare("SELECT * FROM directory WHERE user_active != '' limit $_REQUEST['startp'],$_REQUEST['endp']");
        $sth->execute(array(':county' => $county));

        $c = 1;
        while ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
            echo '<div class="entry';
                 if (($c % 4) == 1) echo ' alpha ';
           // ECHO RESULT STYLES ETC HERE
        $c++;
        }

  $conn = null;        // Disconnect
}
catch(PDOException $e) {
  echo $e->getMessage();
}

Thanks Ripa Saha