SQL 第五章 -- 小型练习项目

use HOUSE
select * from hos_house  --房间信息表
select * from hos_district  --区县表
select * from hos_street    --街道表
select * from hos_type    --房间类型表

--1.内容扩充：临时表
--如果表名前面有#，那么创建的表是临时表，位于tempdb数据库下
--的临时表文件夹下。
create table #mytemp2222
(
id int identity(1,1) primary key not null,
name nvarchar(20)
)

--任务一：分页显示查询出租房信息
--*******************方式一：双top，双order by分页************************
--查询输出第6条~第10条房屋出租信息

--did:区县编号(hos_district)

select top 5 *,hos_district.did
from hos_house,hos_street,hos_district
where  hmid
not in(select top 5 hmid from hos_house)
and hos_house.sid=hos_street.sid
and hos_street.sdid=hos_district.did

--*******************方式二：Row_Number() over(order by id)***************
select * from
(select *,row_number() over(order by hmid) as myid
from hos_house) as temp
where myid between 6 and 10
--*******************方式三：临时表分页***********************************
--查询输出第6条~第10条房屋出租信息
use house
select identity(int,1,1) as myid, UID, SID, HTID, PRICE, TOPIC, CONTENTS, HTIME, COPY
into #housetemp
from hos_house
--通过临时表我们发现，其实实现分页只有两中思路，一种是通过双top，双order by方式，
--另外一种方式就是用一定的手段(可以使系统提供Row_NUmber()函数，也
--可以通过identity(int,1,1)来产生)，在现有表上加上一个自动增长列。
select * from #housetemp
where myid between 6 and 10
--如何将临时表释放
drop table #housetemp
--练习2——查询指定客户发布的出租房屋信息
--需求说明::
--查询“张三”发布的所有出租房屋信息，并显示房屋分布的街道、区县

select DNAME as 区县,SNAME as 街道,HTNAME as 户型,price as 价格,topic as 标题,contents as 描述,htime as 时间,copy as 备注
from hos_district,
hos_street,
hos_type,
hos_house
where hos_house.sid=hos_street.sid
and hos_house.htid=hos_type.htid
and hos_street.sdid=hos_district.did
and uid=
(
select uid from sys_user
where uname='张三'
)
--阶段3：练习——按区县制作房屋出租清单
--根据户型和房屋所在区县和街道,为至少有2个街道有房屋出租的区县制作出租房屋清单
--方式一(推荐)：
select HTNAME as 户型,UNAME as 姓名,DNAME as 区县, SNAME as 街道
from hos_type,sys_user,hos_district,hos_street,hos_house
where hos_house.sid=hos_street.sid
and hos_type.htid=hos_house.htid
and sys_user.uid=hos_house.uid
and hos_district.did=hos_street.sdid
and hos_street.sdid in
(
select  hos_street.sdid
from  hos_street,hos_district,
(select distinct sid from hos_house) as temp
where hos_street.sid=temp.sid
and hos_street.sdid=hos_district.did
group by hos_street.sdid
having count(hos_street.sid)>=2
)

--方式二：
select HTNAME as 户型,UNAME as 姓名,DNAME as 区县, SNAME as 街道
from hos_type,sys_user,hos_district,hos_street,hos_house
where hos_house.sid=hos_street.sid
and hos_type.htid=hos_house.htid
and sys_user.uid=hos_house.uid
and hos_district.did=hos_street.sdid
and hos_house.SID in
(
select hos_street.SID
from hos_street
where sdid in
(
select sdid
from hos_street,(select distinct(SID) from hos_house) as temp
where hos_street.sid=temp.sid
group by sdid
having count(hos_street.SID)>=2
)
)

--阶段4：按季度统计本年发布的房屋出租数量
--要求输出本年1月1日至今的全部出租房屋数量，各区县
--出租房屋数量以及各街道、户型出租房屋数量。
use house
DECLARE @year int
--SET @year = DATEPART(yy,GETDATE())
set @year=2009

SELECT tmp.quarter AS '季度',hos_district.DNAME AS '区县',hos_street.SNAME AS '街道',
hos_type.HTNAME AS '户型',tmp.cnt AS '房屋数量'
FROM (
SELECT SID,HTID,COUNT(*) cnt,DATEPART(qq,HTIME) quarter
FROM hos_house
WHERE DATEPART(yy,HTIME)=@year
GROUP BY DATEPART(qq,HTIME),SID,HTID
) tmp
--INNER JOIN sys_user ON (tmp.UID=sys_user.UID)
INNER JOIN hos_street ON(tmp.SID=hos_street.SID)
INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)
INNER JOIN hos_type ON(tmp.HTID=hos_type.HTID)

UNION

SELECT DATEPART(qq,HTIME),hos_district.DNAME,' 小计 ','  ',COUNT(*) AS '房屋数量'
FROM hos_house
INNER JOIN hos_street ON(hos_house.SID=hos_street.SID)
INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)
WHERE DATEPART(yy,HTIME)=@year
GROUP BY DATEPART(qq,HTIME),hos_district.DNAME

union

SELECT DATEPART(qq,HTIME),' 合计 ','  ','  ',COUNT(*) AS '房屋数量'
FROM hos_house
WHERE DATEPART(yy,HTIME)=@year
GROUP BY DATEPART(qq,HTIME)