删除重复记录保留一条 查询及删除重复记录
查询及删除重复记录
(一) 查找表中多余的重复记录 重复记录是根据单个字段(peopleId)来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > ) 删除表中多余的重复记录 重复记录是根据单个字段(peopleId)来判断 只留有rowid最小的记录 delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > ) and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )> ) 查找表中多余的重复记录(多个字段) select * from vitae a where (a peopleId a seq) in (select peopleId seq from vitae group by peopleId seq having count(*) > ) 删除表中多余的重复记录(多个字段) 只留有rowid最小的记录 delete from vitae a where (a peopleId a seq) in (select peopleId seq from vitae group by peopleId seq having count(*) > ) and rowid not in (select min(rowid) from vitae group by peopleId seq having count(*)> )

查找表中多余的重复记录(多个字段) 不包含rowid最小的记录 select * from vitae a where (a peopleId a seq) in (select peopleId seq from vitae group by peopleId seq having count(*) > ) and rowid not in (select min(rowid) from vitae group by peopleId seq having count(*)> ) (二) 比方说 在A表中存在一个字段“name” 而且不同记录之间的“name”值有可能会相同 现在就是需要查询出在该表中的各记录之间 “name”值存在重复的项 Select Name Count(*) From A Group By Name Having Count(*) > 如果还查性别也相同大则如下: Select Name * Count(*) From A Group By Name * Having Count(*) >
lishixinzhi/Article/program/MySQL/201311/29563