子查询（二）子查询

1 找出住在纽约的代理商的aid值和名字

select  aid aid值,aname 姓名

from agents

where city = 'New York'

2 检索订货记录中所有零件的pid值

select distinct pid 

     from orders 

         order by pid

3 找出至少被两个顾客订购的产品的pid值

select pid

     from (select pid, count(aid) ca 

from orders

group by pid

) a

where a.ca >= 2

order by pid

4 求出有顾客居住的城市的数目

select count(*) 

       from(

           select distinct city 

                from customers 

       )  

5 查询那些订购了某个被代理商a06订购过的产品的顾客的cid值

select distinct cid from orders 

       where pid in(

             select distinct pid from orders where aid = 'a06'

       )order by cid 

6 求出通过住在Duluth和Dallas的代理商订了货的顾客的cid值

select distinct cid from orders

where aid in(

select aid 代理商编号

            from agents

where city = 'Duluth' or city = 'Dallas'

)order by cid

7 检索有关住在Duluth或Dallas的代理商的所有信息

select ag.aid 代理商编号,ag.aname 姓名,ag.city 城市,ag.PERCENTS 佣金百分比,

ord.ORDNO 订单号,ord.CID 客户编号,ord.PID 商品编号,ord.QTY 数量,ord.DOLLARS 总金额

from agents ag inner join orders ord

on ag.aid = ord.aid

where ag.city = 'Duluth' or ag.city = 'Dallas'

8 求出通过住在Duluth或Dallas的代理商订货的所有顾客的姓名和折扣

select cname 姓名,discnt 折扣

from customers

where cid in (

select distinct ord.CID 客户编号

 from agentsag inner join orders ord

                on ag.aid = ord.aid

                where ag.city = 'Duluth' or ag.city = 'Dallas'

)

9 找出订购了产品p05的顾客的名字

select cname 姓名

from customers

where cid in(

select distinct cid from orders

where pid = 'p05'

)

10 分别查询有和没有购买过产品的顾客名称

select distinct cname 姓名

from customers

where cid in (

select distinct cid from orders

)

11 得到从代理商a03处订购了产品p07的顾客的名称 

select * from customers

where cid =(

select cid from orders

where aid = 'a03' and pid = 'p07'

)

12 检索由住在Duluth的顾客和住在New York 的代理商组成的所有订货记录的ordno值（）

select  ordno from orders

where cid in (select cid from customers

where city = 'Duluth') and

aid in (select aid from agents

    where city = 'New York')

order by ordno

13 找出佣金百分率最小的代理商的名称

select aname 姓名

from agents

where percents = (

select min(PERCENTS) 佣金百分率

            from agents

)

14 检索通过代理商a05订货的所有顾客的名字

select cname 姓名

from customers

where cid in (

select distinct cid

          from orders 

where aid = 'a05'

)

15 求出住在New York 或Duluth 并订购了价格超过一美元的所有产品的代理商的aid值

select aid from orders

where aid in (

select distinct aid from orders

where aid in (

select aid from agents where city = 'New York' or

city = 'Duluth'

)

) and DOLLARS/ QTY >= 1

16 找出具有以下性质的顾客的cid 值：如果顾客c006订购了某种产品，那要检索的顾客也订购了该产品

select distinct cid  from orders

where pid in (

select distinct pid

     from orders 

where cid = 'c006'

) order by cid

17 检索对同一产品至少订购了两次的所有顾客的名字

select cname from customers where cid in

(select cid from orders group by cid,pid having count(pid)>=2)

18 求出既订购了产品p01又订购了产品p07的顾客的cid值 

select distinct cid from ordersx  

where pid='p01' and

exists (select * from orders where cid=x.cid and pid='p07')