山东大学数据库系统实验答案

1.create table test4_01 as

(

select *

from pub.STUDENT_41)

alter table test4_01 add sum_score

create table test41 as

(select sum(score) sumscore,sid

from pub.STUDENT_COURSE

group by sid)

update test4_01

set sum_score=(

select sumscore

from test41

where test41.sid=test4_01.sid)

2.create table test4_02

as(select *

from pub.STUDENT_41)

create table test42 as

(select sid,avg(score) avgscore

from pub.STUDENT_COURSE

group by sid)

alter table test4_02 add avg_score numeric(4,1)

update test4_02

set avg_score=(

select avgscore

from test42

where test42.sid=test4_02.sid)

3.create table test4_03 as

(select *

from pub.STUDENT_41)

alter table test4_03 add sum_credit int

create table test43 as

(select sum(credit) sumcredit,sid

from pub.STUDENT_COURSE natural join pub.COURSE

where pub.STUDENT_COURSE.SCORE>=60

and pub.STUDENT_COURSE.SCORE is not null

group by sid)

update test4_03

set sum_credit=(

select sumcredit

from test43

where test43.sid=test4_03.sid)

4.create table test4_04 as

(select *

from pub.STUDENT_41)

update test4_04

set dname=(

select did

from pub.DEPARTMENT

where pub.DEPARTMENT.DNAME=test4_04.dname)

update test4_04

set dname=

(select dname

from pub.STUDENT_41

where test4_04.sid=pub.student_41.sid

)where dname is null

5.

create table test4_05 as

(select *

from pub.STUDENT_41)

alter table test4_05 add sum_score int

alter table test4_05 add avg_score numeric(4,1)

alter table test4_05 add sum_credit int

alter table test4_05 add did varchar(2)

update test4_05

set sum_score=(

select sum_score

from test4_01

where test4_01.sid=test4_05.sid)

update test4_05

set avg_score=(

select avg_score

from test4_02

where test4_02.sid=test4_05.sid)

update test4_05

set sum_credit=(

select sum_credit

from test4_03

where test4_03.sid=test4_05.sid)

update test4_05

set did=(

select did

from pub.DEPARTMENT

where pub.DEPARTMENT.DNAME=test4_05.dname)

where dname in(select dname from pub.DEPARTMENT)

update test4_05

set did=(

select did

from pub.DEPARTMENT_41

where pub.DEPARTMENT_41.DNAME=test4_05.dname)

where dname in(select dname from pub.DEPARTMENT_41）

update test4_05

set did='00'

where did is null

6.create table test4_06 as

(select *

from pub.STUDENT_42)

update test4_06

set name=replace(name,' ','')

7.create table test4_07 as

(select *

from pub.STUDENT_42)

update test4_07

set sex=replace(sex,' ','')

update test4_07

set sex=replace(sex,'性','')

8.create table test4_08 as

(select *

from pub.STUDENT_42)

update test4_08

set class=replace(class,'级','')

9.

create table test4_09 as

(select *

from pub.STUDENT_42)

update test4_09

set age=(2012-extract(year from birthday))

where age is null

10.create table test4_10 as

(select *

from pub.STUDENT_42)

update test4_10

set name=replace(name,' ','')

update test4_10

set sex=replace(sex,' ','')

update test4_10

set sex=replace(sex,'性','')

update test4_10

set class=replace(class,'级','')

update test4_10

set age=(2012-extract(year from birthday))

where age is null

update test4_10

set dname=replace(dname,' ','')