MYSQL 查詢和刪除重複記錄的方法很多，下面就爲您介紹幾種最常用的 MYSQL 查詢和刪除重複記錄的方法，希望對您查詢和刪除重複數據方面能有所幫助。
SQL重複記錄查詢的幾種方法：
1. 查找表中多餘的重複記錄，重複記錄是根據單個字段（peopleId）來判斷
select * from people
where peopleId
in (select peopleId from people
group by peopleId
having count(peopleId) > 1)
2. 刪除表中多餘的重複記錄，重複記錄是根據單個字段（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. 查找表中多餘的重複記錄（多個字段）
select * from vitae a
where (a.peopleId,a.seq)
in (select peopleId,seq from vitae
group by peopleId,seq
having count(*) > 1)
4. 刪除表中多餘的重複記錄（多個字段），只留有 rowid 最小的記錄
delete from vitae a
where (a.peopleId,a.seq)
in (select peopleId,seq from vitae
group by peopleId,seq
having count(*) > 1)
and rowid not in (
select min(rowid) from vitae
group by peopleId,seq having count(*)>1)
5. 查找表中多餘的重複記錄（多個字段），不包含 rowid 最小的記錄
select * from vitae a
where (a.peopleId,a.seq)
in (select peopleId,seq from vitae
group by peopleId,seq
having count(*) > 1)
and rowid not in (
select min(rowid) from vitae
group by peopleId,seq
having count(*)>1)
以上 SQL 記錄重複數據查詢和刪除方法，希望能夠幫助你。