function hook_update_N

Related topics

File

core/lib/Drupal/Core/Extension/module.api.php, line 782

Code

function hook_update_N(&$sandbox) {
    // For non-batch updates, the signature can simply be:
    // function hook_update_N() {
    // Example function body for adding a field to a database table, which does
    // not require a batch operation:
    $spec = [
        'type' => 'varchar',
        'description' => "New Col",
        'length' => 20,
        'not null' => FALSE,
    ];
    $schema = Database::getConnection()->schema();
    $schema->addField('my_table', 'newcol', $spec);
    // Example of what to do if there is an error during your update.
    if ($some_error_condition_met) {
        throw new UpdateException('Something went wrong; here is what you should do.');
    }
    // Example function body for a batch update. In this example, the values in
    // a database field are updated.
    if (!isset($sandbox['progress'])) {
        // This must be the first run. Initialize the sandbox.
        $sandbox['progress'] = 0;
        $sandbox['current_pk'] = 0;
        $sandbox['max'] = Database::getConnection()->query('SELECT COUNT([my_primary_key]) FROM {my_table}')
            ->fetchField();
    }
    // Update in chunks of 20.
    $records = Database::getConnection()->select('my_table', 'm')
        ->fields('m', [
        'my_primary_key',
        'other_field',
    ])
        ->condition('my_primary_key', $sandbox['current_pk'], '>')
        ->range(0, 20)
        ->orderBy('my_primary_key', 'ASC')
        ->execute();
    foreach ($records as $record) {
        // Here, you would make an update something related to this record. In this
        // example, some text is added to the other field.
        Database::getConnection()->update('my_table')
            ->fields([
            'other_field' => $record->other_field . '-suffix',
        ])
            ->condition('my_primary_key', $record->my_primary_key)
            ->execute();
        $sandbox['progress']++;
        $sandbox['current_pk'] = $record->my_primary_key;
    }
    $sandbox['#finished'] = empty($sandbox['max']) ? 1 : $sandbox['progress'] / $sandbox['max'];
    // To display a message to the user when the update is completed, return it.
    // If you do not want to display a completion message, return nothing.
    return t('All foo bars were updated with the new suffix');
}