两张表A,BA表如下:id cname a
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1 数据库 20
1 SQL 30B表如下:id pname b
--------------------------
1 编程 50
如何查询:当A,B两张表id=1时,对a,b字段求和的结果也就是结果要这样:id a+b
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1 100
请前辈们赐教!
-------------------------
1 数据库 20
1 SQL 30B表如下:id pname b
--------------------------
1 编程 50
如何查询:当A,B两张表id=1时,对a,b字段求和的结果也就是结果要这样:id a+b
----------------------------
1 100
请前辈们赐教!
FROM A,B
WHERE A.ID=B.ID AND A.ID=1
GROUP BY A.ID
from (select id,b from tb where id = 1
union all
select id,a from ta where id = 1)
group by id
from (select id,b from tb where id = 1
union all
select id,a from ta where id = 1) a
group by id
(
SELECT A.ID,SUM(A) A FROM A GROUP BY A.ID
)A
,
(
SELECT B.ID,SUM(B) B FROM B GROUP BY B.ID
)B
WHERE A.ID=B.ID
(
select id , val = a from a where id = 1
union all
select id , val = b from b where id = 1
) t
group by id
insert into a values(1 ,'数据库', 20)
insert into a values(1 ,'SQL' ,30)
create table b(id int,pname varchar(10),b int)
insert into b values(1 ,'编程', 50)select id , sum(val) val from
(
select id , val = a from a where id = 1
union all
select id , val = b from b where id = 1
) t
group by iddrop table a , b/*id val
----------- -----------
1 100(所影响的行数为 1 行)
*/