select a.*,case when b.列2 is null then 'trun' else 'false' end as C from a left join b on a.id=B.列2
SELECT A.*,CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1) THEN 'TRUE' ELSE 'FALSE' END AS 'C' FROM A
select a.*,case when b.列2 is null then 'trun' else 'false' end as Cfrom a left join b on a.id=B.列2
DECLARE @TA TABLE([ID] INT, [列1] INT, [列2] INT) INSERT @TA SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 2 UNION ALL SELECT 3, 3, 3 UNION ALL SELECT 4, 4, 4 UNION ALL SELECT 5, 5, 5DECLARE @TB TABLE([ID] INT, [列1] INT, [列2] INT) INSERT @TB SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 1 UNION ALL SELECT 3, 3, 1 UNION ALL SELECT 4, 1, 2 UNION ALL SELECT 5, 2, 2SELECT A.*,CASE WHEN A.[列1]=B.[列1] THEN 'true' ELSE 'false' END AS C FROM @TA AS A LEFT JOIN (SELECT * FROM @TB WHERE 列2=1) AS B ON A.[列1]=B.[列1] /* ID 列1 列2 C ----------- ----------- ----------- ----- 1 1 1 true 2 2 2 true 3 3 3 true 4 4 4 false 5 5 5 false */
DECLARE @TA TABLE([ID] INT, [列1] INT, [列2] INT) INSERT @TA SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 2 UNION ALL SELECT 3, 3, 3 UNION ALL SELECT 4, 4, 4 UNION ALL SELECT 5, 5, 5DECLARE @TB TABLE([ID] INT, [列1] INT, [列2] INT) INSERT @TB SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 1 UNION ALL SELECT 3, 3, 1 UNION ALL SELECT 4, 1, 2 UNION ALL SELECT 5, 2, 2declare @a int set @a=1 select A.ID,列1,列2,c from @TA A, (select row_number() over (order by getdate()) id,case when 列2=@a then 'true' else 'false' end c from @tb) tmp where A.id=tmp.id ID 列1 列2 c ----------- ----------- ----------- ----- 1 1 1 true 2 2 2 true 3 3 3 true 4 4 4 false 5 5 5 false(5 行受影响)
select a.*,case when b.列2 is null then 'trun' else 'false' end as C from a left join b on a.id=B.列2
if object_id('a') is not null drop table a create table a(ID int,列1 int, 列2 int) insert a select 1,1,1 union all select 2,2,2 union all select 3,3,3 union all select 4,4,4 union all select 5,5,5if object_id('b') is not null drop table b create table b (ID int,列1 int, 列2 int) insert b select 1,1,1 union all select 2,2,1 union all select 3,3,1 union all select 4,1,2 union all select 5,2,2 SELECT A.*,CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1) THEN 'TRUE' ELSE 'FALSE' END AS 'C' FROM A /* 1 1 1 TRUE 2 2 2 TRUE 3 3 3 TRUE 4 4 4 FALSE 5 5 5 FALSE */
create table A ([ID] INT, [列1] INT, [列2] INT) INSERT A SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 2 UNION ALL SELECT 3, 3, 3 UNION ALL SELECT 4, 4, 4 UNION ALL SELECT 5, 5, 5create table B ([ID] INT, [列1] INT, [列2] INT) INSERT B SELECT 1, 1, 1 UNION ALL SELECT 2, 2, 1 UNION ALL SELECT 3, 3, 1 UNION ALL SELECT 4, 1, 2 UNION ALL SELECT 5, 2, 2 如果表相符,直接运行以下SQL select M.*,case when N.列1 is null then 'false' else 'ture' end from (select* from A) M left join (select * from B where 列2=1) N on M.ID=N.ID
if object_id('a') is not null drop table a create table a(ID int,列1 int, 列2 int) insert a select 1,1,1 union all select 2,2,2 union all select 3,3,3 union all select 4,4,4 union all select 5,5,5if object_id('b') is not null drop table b create table b (ID int,列1 int, 列2 int) insert b select 1,1,1 union all select 2,2,1 union all select 3,3,1 union all select 4,4,2 union all select 5,5,2SELECT A.*,C=(CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1 AND B.列2=1) THEN 'TRUE' ELSE 'FALSE' END) FROM AID 列1 列2 C ----------- ----------- ----------- ----- 1 1 1 TRUE 2 2 2 TRUE 3 3 3 TRUE 4 4 4 FALSE 5 5 5 FALSE(5 行受影响)
from a left join b on a.id=B.列2
SELECT A.*,CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1) THEN 'TRUE' ELSE 'FALSE' END AS 'C'
FROM A
left join b on a.id=B.列2
DECLARE @TA TABLE([ID] INT, [列1] INT, [列2] INT)
INSERT @TA
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 2 UNION ALL
SELECT 3, 3, 3 UNION ALL
SELECT 4, 4, 4 UNION ALL
SELECT 5, 5, 5DECLARE @TB TABLE([ID] INT, [列1] INT, [列2] INT)
INSERT @TB
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 1 UNION ALL
SELECT 3, 3, 1 UNION ALL
SELECT 4, 1, 2 UNION ALL
SELECT 5, 2, 2SELECT A.*,CASE WHEN A.[列1]=B.[列1] THEN 'true' ELSE 'false' END AS C
FROM @TA AS A LEFT JOIN (SELECT * FROM @TB WHERE 列2=1) AS B
ON A.[列1]=B.[列1]
/*
ID 列1 列2 C
----------- ----------- ----------- -----
1 1 1 true
2 2 2 true
3 3 3 true
4 4 4 false
5 5 5 false
*/
INSERT @TA
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 2 UNION ALL
SELECT 3, 3, 3 UNION ALL
SELECT 4, 4, 4 UNION ALL
SELECT 5, 5, 5DECLARE @TB TABLE([ID] INT, [列1] INT, [列2] INT)
INSERT @TB
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 1 UNION ALL
SELECT 3, 3, 1 UNION ALL
SELECT 4, 1, 2 UNION ALL
SELECT 5, 2, 2declare @a int
set @a=1
select A.ID,列1,列2,c from @TA A, (select row_number() over (order by getdate()) id,case when 列2=@a then 'true' else 'false' end c from @tb) tmp where A.id=tmp.id
ID 列1 列2 c
----------- ----------- ----------- -----
1 1 1 true
2 2 2 true
3 3 3 true
4 4 4 false
5 5 5 false(5 行受影响)
select a.*,case when b.列2 is null then 'trun' else 'false' end as C
from a left join b on a.id=B.列2
if object_id('a') is not null drop table a
create table a(ID int,列1 int, 列2 int)
insert a
select 1,1,1
union all select 2,2,2
union all select 3,3,3
union all select 4,4,4
union all select 5,5,5if object_id('b') is not null drop table b
create table b (ID int,列1 int, 列2 int)
insert b
select 1,1,1
union all select 2,2,1
union all select 3,3,1
union all select 4,1,2
union all select 5,2,2
SELECT A.*,CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1) THEN 'TRUE' ELSE 'FALSE' END AS 'C'
FROM A
/*
1 1 1 TRUE
2 2 2 TRUE
3 3 3 TRUE
4 4 4 FALSE
5 5 5 FALSE */
create table A ([ID] INT, [列1] INT, [列2] INT)
INSERT A
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 2 UNION ALL
SELECT 3, 3, 3 UNION ALL
SELECT 4, 4, 4 UNION ALL
SELECT 5, 5, 5create table B ([ID] INT, [列1] INT, [列2] INT)
INSERT B
SELECT 1, 1, 1 UNION ALL
SELECT 2, 2, 1 UNION ALL
SELECT 3, 3, 1 UNION ALL
SELECT 4, 1, 2 UNION ALL
SELECT 5, 2, 2
如果表相符,直接运行以下SQL
select M.*,case when N.列1 is null then 'false' else 'ture' end
from
(select* from A) M left join
(select * from B where 列2=1) N
on M.ID=N.ID
create table a(ID int,列1 int, 列2 int)
insert a
select 1,1,1 union all
select 2,2,2 union all
select 3,3,3 union all
select 4,4,4 union all
select 5,5,5if object_id('b') is not null drop table b
create table b (ID int,列1 int, 列2 int)
insert b
select 1,1,1 union all
select 2,2,1 union all
select 3,3,1 union all
select 4,4,2 union all
select 5,5,2SELECT A.*,C=(CASE WHEN EXISTS(SELECT 1 FROM B WHERE A.ID=B.列1 AND B.列2=1) THEN 'TRUE' ELSE 'FALSE' END)
FROM AID 列1 列2 C
----------- ----------- ----------- -----
1 1 1 TRUE
2 2 2 TRUE
3 3 3 TRUE
4 4 4 FALSE
5 5 5 FALSE(5 行受影响)