mysql语法问题，谢谢解答

Question

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)

Answer 1

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)