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Question

表A
buyid      sellid          qu
1              2             浦东区
3              4             闵行区
5             6              徐汇区
表B
peopleid             brithday
1                        1986.9.24
2                        1966.6.6
3                        1987.8.4
4                        1965.2.4
5                        1985.3.21
6                        1977.12.1说明：buyid(买家) 和sellid（卖家) 分别和peopleid 相连.
结果
------------------
区域           买家年龄                                 卖家年龄
---------------------------------------------------------------
浦东区        当前时间-1986.9.24         当前时间-1966.6.6
闵行区        当前时间-1987.8.4         当前时间-1965.2.4
 徐汇区       当前时间-1985.3.21         当前时间-1977.12.1

Answer 1

create table #A (
buyid int,
sellid int,
qu varchar(20))insert #A
select 1,2,'浦东'
union all
select 3,4,'闵行区'
union all
select 5,6,'徐汇区'create table #B (
peopleid int,
birthday varchar(20))insert #B
select 1,'1986.9.24'
union all
select 2,'1966.6.6'
union all
select 3,'1987.8.4'
union all
select 4,'1965.2.4'
union all
select 5,'1985.3.21'
union all
select 6,'1977.12.1'select '区域' = qu,'买家年龄'=datediff(year,convert(datetime,B1.birthday),getdate()),
'卖家年龄'=datediff(year,convert(datetime,B2.birthday),getdate())
from #A,#B B1,#B B2
where #A.buyid = B1.peopleid and #A.sellid = B2.peopleid
drop table #A
drop table #B
-----------------------------------
--测试数据
浦东 21 41
闵行区 20 42
徐汇区 22 30

Answer 2

select qu,c.birthday as 买家年龄 ,d.birthday as 卖家年龄 
from 
(select a.sellid,a.qu,b.brithday from a,b where a.buyid = b.peopleid ) c,(select a.sellid,a.qu,b.brithday from a,b where a.sellid = b.peopleid) d 
where c.sellid = d.sellid

Answer 3

from #A,#B B1,#B B2
 怎么理解啊？