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Object-relational mapping

Introduction​

This is a short guide to the main Live Helper Chat classes and how to fetch data from the database.

Live Helper Chat uses Zeta Components for database interactions. While these components are older, they have served the project's needs well since its inception over 10 years ago.

The Live Helper Chat classes that interact with the database are located in the following directories:

https://github.com/LiveHelperChat/livehelperchat/tree/master/lhc_web/pos

The model classes are located at:

https://github.com/LiveHelperChat/livehelperchat/tree/master/lhc_web/lib/models

Almost all classes that work with the database use the erLhcoreClassDBTrait trait. Refer to this trait to see the available methods.

Most common methods​


try {
    // Begin transaction
    $db = ezcDbInstance::get();
    $db->beginTransaction();
        
    // Save/Update new object
    $chat = new erLhcoreClassModelChat();
    $chat->saveThis();

    // Change attribute
    $chat->nick = 'Live Helper Chat';

    // Update only the 'nick' field
    $Chat->saveThis(['update' => ['nick']]);

    // Update all fields
    $Chat->saveThis();

    // Sync record and lock it
    $chat->syncAndLock();

    // Delete object
    $chat->removeThis();

    // Fetch by primary key
    erLhcoreClassModelChat::fetch(1);

    // Fetch and lock record
    erLhcoreClassModelChat::fetchAndLock(1);

    // Search by department
    // For all filtering options, see filter examples
    erLhcoreClassModelChat::getList(['limit' => 5, 'offset' => 5, 'filter' => ['dep_id' => 5]]);

    // Get the number of records
    erLhcoreClassModelChat::getCount(['limit' => 5, 'offset' => 5, 'filter' => ['dep_id' => 5]]);

    $db->commit();

} catch (Exception $e) {
    $db->rollback();
}


// Direct query
$stmt = $db->prepare('SELECT id FROM lh_users_online_session WHERE user_id = :user_id AND lactivity > :lactivity_back');
$stmt->bindValue(':user_id', $this->userid, PDO::PARAM_INT);
$stmt->bindValue(':lactivity_back', time() - 40, PDO::PARAM_INT);
$stmt->execute();

// If you are just updating something, you can skip this part.
$id = $stmt->fetch(PDO::FETCH_COLUMN); // Change how fetch should work.

Filtering options​

<className>::getList and <className>::getCount support the following arguments. See the conditions method.

['filter' => ['column' => 'required_value']]; // `column` = 'required_value'

['filterin' => ['column' => [1, 2]]]; // `column` IN (1, 2)

['filterlt' => ['column' => 5]]; // `column` < 5

['filtergt' => ['column' => 5]]; // `column` > 5

['filtergte' => ['column' => 5]]; // `column` >= 5

['filterlte' => ['column' => 5]]; // `column` <= 5

['filternot' => ['column' => 'lhc']]; // `column` != 'lhc'

['filterlike' => ['column' => 'lhc']]; // `column` LIKE ('%lhc%')

['filterlikeright' => ['column' => 'lhc']]; // `column` LIKE ('lhc%')

['filternotin' => ['column' => [1, 2]]]; // `column` NOT IN (1, 2)