SQL去重复记录,留一条符合条件记录

declare @tbl table(name varchar(20),age datetime)

insert into @tbl 

select 'jacky','1985-12-23' union 

select 'myjacky','1986-12-10' union

select 'myjacky','1986-12-12' union

select 'jacky','1988-09-23'



--方法一

select a.* from @tbl a 

inner join (select max(age) as age,name from @tbl group by name) b

on a.name=b.name and a.age=b.age



--方法二

select a.* from @tbl a where 1>(select count(*) from @tbl where name = a.name and age > a.age) order by a.name



--方法三

select a.* from @tbl a where not exists(select 1 from @tbl where name = a.name and age < a.age)



--方法四

select a.* from @tbl a where age = (select min(age) from @tbl where name = a.name) order by a.name