SQL查询时去除重复值
方法1： delete from test where id not in (select max(id) from test with(nolock) group by bookname,nuthor having count(id) > 0)方法2：WITH myd AS
(
SELECT ROW_NUMBER()
OVER(PARTITION BY bookname,nuthor ORDER BY ID )
AS NUM,* FROM test
)
DELETE FROM myd
WHERE NUM != 1
页:
[1]