SELECT
	CONCAT("'", id) AS id ,...,
IF (
	ISNULL(field1),
	'',
	(
		SELECT
			group_concat(
				CONCAT_WS(
					'|',
					IFNULL(NAME, ''),
					IFNULL(type, ''),
					IFNULL(iname, '')
				) SEPARATOR ';'
			)
		FROM
			child_table
		WHERE
			rid = a.rid
	)
) AS artist
FROM
	parent_table