我是删除数据库里 有某些字段相同的记录只保留一个,这样怎么做?DELETE FROM a
FROM TollData AS a CROSS JOIN
a
WHERE EXISTS
(SELECT 1 AS Expr1
FROM TollData
WHERE (CardID = a.CardID) AND (StCardDate = a.starddate) AND (Balance = a.Balance))
FROM TollData AS a CROSS JOIN
a
WHERE EXISTS
(SELECT 1 AS Expr1
FROM TollData
WHERE (CardID = a.CardID) AND (StCardDate = a.starddate) AND (Balance = a.Balance))
解决方案 »
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