code: public function get_columns() {
  		return array(
  			'id'        => new IntegerBased( 'BIGINT', 'id', array( 'NOT NULL', 'auto_increment' ), array( 20 ) ),
  			'message'   => new StringBased( 'VARCHAR', 'message', array(), array( 255 ) ),
  			'level'     => new StringBased( 'VARCHAR', 'level', array(), array( 20 ) ),
  			'lgroup'    => new StringBased( 'VARCHAR', 'lgroup', array(), array( 20 ) ),
  			'time'      => new DateTime( 'time' ),
  			'user'      => new ForeignUser( 'user' ),
  			'ip'        => new StringBased( 'VARCHAR', 'ip', array(), array( 45 ) ),
  			'exception' => new StringBased( 'VARCHAR', 'exception', array(), array( 255 ) ),
  			'trace'     => new StringBased( 'LONGTEXT', 'trace' ),
  			'context'   => new StringBased( 'LONGTEXT', 'context' ),
  		);
  	}
docs: Columns in the table.
  
  key => sprintf field type
  
  @since 1.0
  
  @return array