mysql语法问题,谢谢解答

SELECT
MTIANTRA_ID ,
MTIANTRA_PARENTLIST ,
MTIANTRA_LEV ,
MTIANTRA_PARENTID ,
MTIANTRA_THISIDALL
FROM
MT100TRA
WHERE
MTIANTRA_ID = 'TRA100001'
AND
MTIANTRA_THISIDALL = (SELECT MTIANTRA_PARENTID, MTIANTRA_THISIDALL FROM MT100TRA WHERE MTIANTRA_PARENTID = 'TRA100001' order by MTIANTRA_PARENTID,MTIANTRA_THISIDALL desc limit 1)

帮看看哪里有错误,报错Operand should contain 1 column(s)

倒数第二行,MTIANTRA_THISIDALL = 后边应该是个值,而非集合。
MTIANTRA_THISIDALL = (SELECT MTIANTRA_PARENTID, MTIANTRA_THISIDALL FROM MT100TRA WHERE MTIANTRA_PARENTID = 'TRA100001' order by MTIANTRA_PARENTID,MTIANTRA_THISIDALL desc limit 1)

可以这样:
MTIANTRA_THISIDALL = (SELECT MTIANTRA_THISIDALL FROM MT100TRA WHERE MTIANTRA_PARENTID = 'TRA100001' order by MTIANTRA_PARENTID,MTIANTRA_THISIDALL desc limit 1)

(SELECT MTIANTRA_PARENTID, MTIANTRA_THISIDALL FROM MT100TRA WHERE MTIANTRA_PARENTID = 'TRA100001' order by MTIANTRA_PARENTID,MTIANTRA_THISIDALL desc limit 1)

返回的是[ MTIANTRA_PARENTID, MTIANTRA_THISIDALL] 但是 缺付给 MTIANTRA_THISIDALL单个变量