Chris@0: /**
Chris@0:  * Implements hook_update_N().
Chris@0:  */
Chris@0: function {{ machine_name }}_update_N(&$sandbox) {
Chris@0:   // For non-batch updates, the signature can simply be:
Chris@0:   // function {{ machine_name }}_update_N() {
Chris@0: 
Chris@0:   // Example function body for adding a field to a database table, which does
Chris@0:   // not require a batch operation:
Chris@0:   $spec = [
Chris@0:     'type' => 'varchar',
Chris@0:     'description' => "New Col",
Chris@0:     'length' => 20,
Chris@0:     'not null' => FALSE,
Chris@0:   ];
Chris@0:   $schema = Database::getConnection()->schema();
Chris@0:   $schema->addField('mytable1', 'newcol', $spec);
Chris@0: 
Chris@0:   // Example of what to do if there is an error during your update.
Chris@0:   if ($some_error_condition_met) {
Chris@0:     throw new UpdateException('Something went wrong; here is what you should do.');
Chris@0:   }
Chris@0: 
Chris@0:   // Example function body for a batch update. In this example, the values in
Chris@0:   // a database field are updated.
Chris@0:   if (!isset($sandbox['progress'])) {
Chris@0:     // This must be the first run. Initialize the sandbox.
Chris@0:     $sandbox['progress'] = 0;
Chris@0:     $sandbox['current_pk'] = 0;
Chris@0:     $sandbox['max'] = Database::getConnection()->query('SELECT COUNT(myprimarykey) FROM {mytable1}')->fetchField() - 1;
Chris@0:   }
Chris@0: 
Chris@0:   // Update in chunks of 20.
Chris@0:   $records = Database::getConnection()->select('mytable1', 'm')
Chris@0:     ->fields('m', ['myprimarykey', 'otherfield'])
Chris@0:     ->condition('myprimarykey', $sandbox['current_pk'], '>')
Chris@0:     ->range(0, 20)
Chris@0:     ->orderBy('myprimarykey', 'ASC')
Chris@0:     ->execute();
Chris@0:   foreach ($records as $record) {
Chris@0:     // Here, you would make an update something related to this record. In this
Chris@0:     // example, some text is added to the other field.
Chris@0:     Database::getConnection()->update('mytable1')
Chris@0:       ->fields(['otherfield' => $record->otherfield . '-suffix'])
Chris@0:       ->condition('myprimarykey', $record->myprimarykey)
Chris@0:       ->execute();
Chris@0: 
Chris@0:     $sandbox['progress']++;
Chris@0:     $sandbox['current_pk'] = $record->myprimarykey;
Chris@0:   }
Chris@0: 
Chris@0:   $sandbox['#finished'] = empty($sandbox['max']) ? 1 : ($sandbox['progress'] / $sandbox['max']);
Chris@0: 
Chris@0:   // To display a message to the user when the update is completed, return it.
Chris@0:   // If you do not want to display a completion message, return nothing.
Chris@0:   return t('All foo bars were updated with the new suffix');
Chris@0: }