sql 多表统计问题 - MS-SQL Server / 应用实例

表A
  日期 支出金额 
  2010-04-01 120
  2010-04-02 250
  2010-05-01 100 
  2010-05-04 200
  2010-05-06 300


表B
  日期 收入金额 
  2010-04-05 100
  2010-04-07 200
  2010-05-05 300 
  2010-05-07 400
  2010-05-08 500

怎么用一个SQl语名得到如下
  日期 支出金额 收入金额 
  2010-04 370 300
  2010-05 600 1200

用一个SQL语句同时统计两个表不同字段










 

---

SQL code:
---测试数据---
if object_id('[A]') is not null drop table [A]
go
create table [A]([日期] datetime,[支出金额] int)
insert [A]
select '2010-04-01',120 union all
select '2010-04-02',250 union all
select '2010-05-01',100 union all
select '2010-05-04',200 union all
select '2010-05-06',300
if object_id('[B]') is not null drop table [B]
go
create table [B]([日期] datetime,[收入金额] int)
insert [B]
select '2010-04-05',100 union all
select '2010-04-07',200 union all
select '2010-05-05',300 union all
select '2010-05-07',400 union all
select '2010-05-08',500

---查询---
select convert(varchar(7),日期,120) 日期,sum(支出金额) 支出金额,sum(收入金额) 收