RainLab\Builder\Classes\TableMigrationCodeGenerator::getChangedOrRemovedPrimaryKey PHP Method

    protected function getChangedOrRemovedPrimaryKey($tableDiff)
    {
        foreach ($tableDiff->changedIndexes as $index) {
            if ($index->isPrimary()) {
                return $index;
            }
        }
        foreach ($tableDiff->removedIndexes as $index) {
            if ($index->isPrimary()) {
                return $index;
            }
        }
        return null;
    }