怎樣查詢數(shù)據(jù)庫中重復(fù)的數(shù)據(jù)？1、查找表中多余的重復(fù)記錄，重復(fù)記錄是根據(jù)單個字段（peopleId）來判斷select * from peoplewhere peopleId in (select

怎樣查詢數(shù)據(jù)庫中重復(fù)的數(shù)據(jù)？

1、查找表中多余的重復(fù)記錄，重復(fù)記錄是根據(jù)單個字段（peopleId）來判斷

select * from peoplewhere peopleId in (select peopleId from people group by peopleId having count (peopleId) > 1)

2、刪除表中多余的重復(fù)記錄，重復(fù)記錄是根據(jù)單個字段（peopleId）來判斷，只留有rowid最小的記錄

delete from people where peopleId in (select peopleId from people group by peopleId having count (peopleId) > 1)and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)

3、查找表中多余的重復(fù)記錄（多個字段）

select * from vitae awhere (a.peopleId，a.seq) in (select peopleId，seq from vitae group by peopleId，seq having

如何查找數(shù)據(jù)庫中的重復(fù)數(shù)據(jù)？

下面以 sqlserver數(shù)據(jù)庫為例進(jìn)行說明。 select * from TableA where b in (select b from TableA group by b having count(b) > 1) 這樣就列舉出了b字段所有的重復(fù)數(shù)據(jù)，可以根據(jù)對應(yīng)的行號，取得位于第幾行。 如果要查詢a字段或者c字段重復(fù)數(shù)據(jù)，可以相應(yīng)的把上面的b字段替換成a字段或c字段即可。 舉例： 1、創(chuàng)建表student 2、查詢語句: select * from student where name in (select name from student group by name having count(name ) > 1) 這樣就查出名字重復(fù)列，以及行號id。

如何查找數(shù)據(jù)庫中的重復(fù)數(shù)據(jù)？

如果是跨庫的話，要看數(shù)據(jù)庫是否支持跨庫的計算。例如，oracle的透明網(wǎng)關(guān)就支持連接其他類型的數(shù)據(jù)庫，用sql做跨庫計算。不過性能不是特別好。 如果你的數(shù)據(jù)庫都不支持跨庫，那么可以用ETL工具，把數(shù)據(jù)抽取到一個數(shù)據(jù)庫中，在用sql計算?；蛘哂镁幊坦ぞ呃纾簀ava、python、esproc等等，把數(shù)據(jù)從各個庫中取出來計算。