RainLab\Builder\Classes\TableMigrationCodeGenerator::findPrimaryKeyIndex PHP Метод

    protected function findPrimaryKeyIndex($indexes, $table)
    {
        /*
         * This method ignores auto-increment primary keys
         * as they are managed with the increments() method
         * instead of the primary().
         */
        foreach ($indexes as $index) {
            if (!$index->isPrimary()) {
                continue;
            }
            if ($this->indexHasAutoincrementColumns($index, $table)) {
                continue;
            }
            return $index;
        }
        return null;
    }