题目如下:
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有如下四个关系模式:
PRODUCT(MAKER,MODEL,TYPE)
PC(MODEL,SPEED,RAM,HD,CD,PRICE)
LAPTOP(MODEL,SPEED,RAM,SCREEN,PRICE)
PRINTER(MODEL,COLOR,TYPE,PRICE)关系PRODUCTD的数据
MAKER MODEL TYPE
A 1001 pc
A 1002 pc
B 1003 pc
C 1004 printer
D 1005 laptop关系PC的数据
MODEL SPEED RAM HD CD PRICE
1001 133 16 1.6 6x 1595
1002 166 16 1.6 8x 1900
1003 200 32 2.0 8x 2100关系LAPTOP的数据
MODEL SPEED RAM HD SCREEN PRICE
1005 133 166 1.1 11.1 3000关系PRINTER的数据
MODEL COLOR TYPE PRICE
1004 true laser 1500试用SQL定义它们。
-----------------------------------------------------我就没明白,“用SQL定义它们”是什么意思,因为手头没有书,也没办法查例子
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有如下四个关系模式:
PRODUCT(MAKER,MODEL,TYPE)
PC(MODEL,SPEED,RAM,HD,CD,PRICE)
LAPTOP(MODEL,SPEED,RAM,SCREEN,PRICE)
PRINTER(MODEL,COLOR,TYPE,PRICE)关系PRODUCTD的数据
MAKER MODEL TYPE
A 1001 pc
A 1002 pc
B 1003 pc
C 1004 printer
D 1005 laptop关系PC的数据
MODEL SPEED RAM HD CD PRICE
1001 133 16 1.6 6x 1595
1002 166 16 1.6 8x 1900
1003 200 32 2.0 8x 2100关系LAPTOP的数据
MODEL SPEED RAM HD SCREEN PRICE
1005 133 166 1.1 11.1 3000关系PRINTER的数据
MODEL COLOR TYPE PRICE
1004 true laser 1500试用SQL定义它们。
-----------------------------------------------------我就没明白,“用SQL定义它们”是什么意思,因为手头没有书,也没办法查例子
并将他们的关系建好。之后就是插入测试数据。
然后insert xxx吧?
那在SQL SERVER里建好了,生成SQL语句就行吧~?
create table PRODUCTD (MAKER varchar(1),MODEL int,TYPE varchar(7))
go
insert into PRODUCTD
select 'A',1001,'pc' union all
select 'A',1002,'pc' union all
select 'B',1003,'pc' union all
select 'C',1004,'printer' union all
select 'D',1005,'laptop'
goif object_id('PC') is not null drop table PC
create table PC (MODEL int,SPEED int,RAM int,HD numeric(2,1),CD varchar(2),PRICE int)
go
insert into PC
select 1001,133,16,1.6,'6x',1595 union all
select 1002,166,16,1.6,'8x',1900 union all
select 1003,200,32,2.0,'8x',2100
goif object_id('LAPTOP') is not null drop table LAPTOP
create table LAPTOP (MODEL int,SPEED int,RAM int,HD numeric(2,1),SCREEN numeric(3,1),PRICE int)
go
insert into LAPTOP
select 1005,133,166,1.1,11.1,3000
goif object_id('PRINTER') is not null drop table PRINTER
create table PRINTER (MODEL int,COLOR varchar(4),TYPE varchar(5),PRICE int)
go
insert into PRINTER
select 1004,'true','laser',1500
go