分享SQL Server删除重复行的6个方法

SELECT column1, column2, ..., columnN
FROM table_name
GROUP BY column1, column2, ..., columnN
HAVING COUNT(*) > 1;

DELETE FROM table_name
WHERE column1, column2, ..., columnN IN
(
    SELECT column1, column2, ..., columnN
    FROM table_name
    GROUP BY column1, column2, ..., columnN
    HAVING COUNT(*) > 1
);

SELECT first_name, last_name, email
FROM employees
GROUP BY first_name, last_name, email
HAVING COUNT(*) > 1;

DELETE FROM employees
WHERE (first_name, last_name, email) IN
(
    SELECT first_name, last_name, email
    FROM employees
    GROUP BY first_name, last_name, email
    HAVING COUNT(*) > 1
);

create table Table1
(
       id int identity(1,1) primary key,
       col1 char(5),
       col2 datetime,
       col3 int
)
--筛选出重复数据（ID不同，其它列都相同）
with a as
(
    select ROW_NUMBER() over(order by id desc) as rownumber,Table1.*
    from Table1    
),
b as
(
        select min(rownumber) as minRow from a    
    group by col1,col2,col3
)
select id,a.*,b.minRow 
from a left outer join b on a.rownumber     = b.minRow 
        where b.minRow is null

delect table where id not in (
select max(id) from table group by col1,col2,col3...
)

select * into #aa from table group by id1,id2,....
delete table
insert into table
select * from #aa

select identity(int,1,1) as id,* into #temp from tabel
delect # where id not in (
select max(id) from # group by col1,col2,col3...)
delect table
inset into table(...)
select ..... from #temp

select * from table where col1+','+col2+','...col5 in (
select max(col1+','+col2+','...col5) from table
where having count(*)>1
group by col1,col2,col3,col4

select identity(int,1,1) as id,* into #temp from tabel
select * from #temp where id in (
select max(id) from #emp where having count(*)>1 group by col1,col2,col3...)

select distinct * into #temp from tablename
delete tablename
go
insert tablename select * from #temp Sqlclub
go
drop table #temp