去除表中重复的数据
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表數(shù)據(jù)如下:
查詢(xún)表中重復(fù)的數(shù)據(jù):
SELECT * FROM t_class WHERE classname IN (SELECT classname FROM t_class GROUP BY classname HAVING COUNT(classname) > 1) 結(jié)果如下:
顯示出來(lái)的數(shù)據(jù),沒(méi)有重復(fù)的數(shù)據(jù):
SELECT classname FROM t_class GROUP BY classname HAVING COUNT(classname) >= 1
轉(zhuǎn)載于:https://my.oschina.net/chainlong/blog/173967
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