SqlServer 列数据比对 转载整理

 DECLARE   @A table (col1 int)
insert into  @A select 1
insert into  @A select 1
insert into  @A select 2
insert into @A select 3
insert into  @A select 4
insert into  @A select 4
insert into  @A select 5
insert into  @A select null
insert into  @A  select null
DECLARE  @B table (col2 int)
insert into  @B select null
insert into  @B select 1
insert into  @B select 2
insert into  @B select 3
DECLARE  @C table (col3 int)
insert into  @C select 1
insert into  @C select 5
insert into  @C select 6

--找出A表的col1列不存在c表col1列的所有非重复值

--SELECT col1 FROM  @A
--EXCEPT
--SELECT col3 FROM  @c

--找出A表的col1列存在c表col1列的所有非重复值

--SELECT col1 FROM  @A
--INTERSECT

--SELECT col3 FROM  @c

-- 1，找出B表的col1列存在B表col1列的所有非重复值 

--2，找出A表的col1列不存在1比对列的所有非重复值

SELECT col1 FROM  A 
EXCEPT
SELECT col2 FROM  B
INTERSECT --优先执行
SELECT col3 FROM  C