散分喽，解决一个sql小问题

[足篮智者]

create database aa
create table tt1
(
typename varchar(10),
lan int
)
create table tt2
(
typename varchar(10),
lan int
)
insert into tt1 values ('22',5)
insert into tt1 values ('11',2)
insert into tt2 values ('22',4)
insert into tt2 values ('23',7)

把typename=22的，就是重复lan的相加，不重复lan的不加，sql查询咋写，，两张表结构一模一样，求解
结果如下：
typename lan
22 9
11 2
23 7

[jwdream2008]

select typename,sum(lan) as 'lan' from 
(
select typename,lan from tt1
union all
select typename,lan from tt2
) T

[jwdream2008]

select T.[typename],sum(T.[lan]) as 'lan' from 
(
select typename,lan from tt1
union all
select typename,lan from tt2
) T
group by T.[typename]

[yhtapmys]

[Quote=引用 2 楼 jwdream2008 的回复:]
SQL code
select T.[typename],sum(T.[lan]) as 'lan' from
(
select typename,lan from tt1
union all
select typename,lan from tt2
) T
group by T.[typename]
[/Quote]

up

[水族杰纶]

[Quote=引用 2 楼 jwdream2008 的回复:]
SQL code
select T.[typename],sum(T.[lan]) as 'lan' from
(
select typename,lan from tt1
union all
select typename,lan from tt2
) T
group by T.[typename]
[/Quote]
。。。

[「已注销」]

SELECT m.typename,SUM(m.lan)lan FROM 
(
SELECT * FROM tt1 t
UNION
SELECT * FROM tt2
)m
GROUP BY m.typename
ORDER BY m.typename

typename   lan
---------- -----------
11         2
22         9
23         7

(3 row(s) affected)