我有一个包含两个字段的表,a和b。在a = b和b = a的意义上,一些记录是重复的。我想删除这些记录。
考虑一下:
declare @temp table (a int, b int)
insert into @temp values (1, 2)
insert into @temp values (3, 4)
insert into @temp values (4, 3)
insert into @temp values (5, 6)
--delete 3, 4 or 4, 3
select * from @temp
/*
a | b
--|--
1 | 2
3 | 4
5 | 6
or (I don't care which one)
a | b
--|--
1 | 2
4 | 3
5 | 6
*/
我怎样才能做到这一点?它需要支持Microsoft SQL Server 2000及更高版本。
答案 0 :(得分:5)
DELETE x
FROM TableName x
INNER JOIN
(
SELECT a.A, a.B
FROM tableName a
INNER JOIN tableName b
ON ((a.A = b.A AND a.b = b.b) OR
(a.A = b.B AND a.b = b.A)) AND
a.a > b.a
) y ON x.A = y.A AND x.B = y.B
答案 1 :(得分:1)
这是针对较新版本的SQL Server
的解决方案declare @temp table (a int, b int)
insert into @temp values (1, 2)
insert into @temp values (3, 4)
insert into @temp values (4, 3)
insert into @temp values (5, 6)
insert into @temp values (6, 5)
--delete 3, 4 or 4, 3
delete t3
--select *
from
(select t1.a, t1.b,rank() over (partition by t2.a +t2.b order by t1.a) as row_number from @temp t1
join @temp t2 on t2.a = t1.b and t2.b = t1.a)c
join @temp t3 on c.a =t3.a and c.b = t3.b
where c.row_number <>1
select * from @temp
发布只是为了搜索同一事物的其他人显示更新的语法。