怎樣查詢(xún)數(shù)據(jù)庫(kù)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(gè)字段（peopleId）來(lái)判斷select * from peoplewhere peopleId in (select

怎樣查詢(xún)數(shù)據(jù)庫(kù)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(gè)字段（peopleId）來(lái)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(gè)字段（peopleId）來(lái)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(gè)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(kù)中的重復(fù)數(shù)據(jù)？

下面以 sqlserver數(shù)據(jù)庫(kù)為例進(jìn)行說(shuō)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(duì)應(yīng)的行號(hào)，取得位于第幾行。 如果要查詢(xún)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(xún)語(yǔ)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(hào)id。

如何查找數(shù)據(jù)庫(kù)中的重復(fù)數(shù)據(jù)？

如果是跨庫(kù)的話，要看數(shù)據(jù)庫(kù)是否支持跨庫(kù)的計(jì)算。例如，oracle的透明網(wǎng)關(guān)就支持連接其他類(lèi)型的數(shù)據(jù)庫(kù)，用sql做跨庫(kù)計(jì)算。不過(guò)性能不是特別好。 如果你的數(shù)據(jù)庫(kù)都不支持跨庫(kù)，那么可以用ETL工具，把數(shù)據(jù)抽取到一個(gè)數(shù)據(jù)庫(kù)中，在用sql計(jì)算?；蛘哂镁幊坦ぞ呃纾簀ava、python、esproc等等，把數(shù)據(jù)從各個(gè)庫(kù)中取出來(lái)計(jì)算。