Question

我正在尝试合并两个表，我想使用GROUP BY来修复以下错误：

The MERGE statement attempted to UPDATE or DELETE the same row more than once. This happens when a target row matches more than one source row. A MERGE statement cannot UPDATE/DELETE the same row of the target table multiple times. Refine the ON clause to ensure a target row matches at most one source row, or use the GROUP BY clause to group the source rows.

GROUP BY子句究竟在哪里？

MERGE dbo.MyTarget targ
USING dbo.MySource src
ON (targ.Identifier = src.Identifier
    AND targ.Name = src.ConstituentName
    AND targ.Ticker = src.ConstituentTicker
    AND (targ.CUSIP = src.CUSIP OR targ.ISIN = src.ISIN OR targ.SEDOL = src.SEDOL))
WHEN MATCHED THEN
-- update values
;

Answer 1

这样的事情：

MERGE dbo.MyTarget targ
USING (SELECT ... FROM dbo.MySource GROUP BY .....) src
ON (targ.Identifier = src.Identifier
    AND targ.Name = src.ConstituentName
    AND targ.Ticker = src.ConstituentTicker
    AND (targ.CUSIP = src.CUSIP OR targ.ISIN = src.ISIN OR targ.SEDOL = src.SEDOL))
WHEN MATCHED THEN
-- update values
;

如何在SQL MERGE语句中使用GROUP BY子句？

1 个答案: