Sql语句 表中相同的记录(某个字段)只显示一条，按照时间排序显示最大或最小

Posted 2023-04-27

Sql语句 表中相同的记录只显示一条，按照时间排序 如: Name列有重复，Time列不重复，则只显示Time列最大或最小的一条，请问sql语句应该是怎么写.

参考技术A 补充下一楼的，应该是这样子：
select name,time from table where (name,time) in(select name,max(time) from table group by name) 参考技术B select Name,max(Time) ad time from 表名 group by Name order by time 参考技术C 最大的一条:
select name,time from table where time in(select name,max(time) from table group by name) 参考技术D select name,max(time) time from table group by name

几个删除重复记录的SQL语句

参考技术A 用SQL语句,删除掉重复项只保留一条在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢
1、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) > 1)
2、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 peopleName in (select peopleName from people group by peopleName having count(peopleName) > 1) and peopleId not in (select min(peopleId) from people group by peopleName having count(peopleName)>1)
3、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(*) > 1)
4、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(*) > 1) and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)

5、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(*) > 1) and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)

6.消除一个字段的左边的第一位：
update tableName set [Title]=Right([Title],(len([Title])-1)) where Title like '村%'

7.消除一个字段的右边的第一位：
update tableName set [Title]=left([Title],(len([Title])-1)) where Title like '%村'

8.假删除表中多余的重复记录（多个字段），不包含rowid最小的记录
update vitae set ispass=-1where peopleId in (select peopleId from vitae group by peopleId