public function primaryKey($length = null)
    {
        return $this->getDb()->getSchema()->createColumnSchemaBuilder(Schema::TYPE_PK, $length);
    }
public function primaryKey($length = null)
    {
        return $this->getDb()->getSchema()->createColumnSchemaBuilder(Schema::TYPE_PK, $length);
    }
public function primaryKey ( $ length = null ) { return $ this -> getDb ( ) -> getSchema ( ) -> createColumnSchemaBuilder ( Schema :: TYPE_PK , $ length ) ; }
Creates a primary key column.
@param int $length column size or precision definition.
This parameter will be ignored if not supported by the DBMS.
@return ColumnSchemaBuilder the column instance which can be further customized.
@since 2.0.6
Creates a primary key column .