Bài tập câu hỏi trắc nghiệm SQL

Exercise 1
Q1
ONLINE CONTESTS system organises contests on various topics. Each contest on a
particular topic has a set of 5 questions to be answered, and is sponsored by a company.
The following tables are maintained within database by the system :



Table : CONTEST Table : COMPANY
Column Description Column Description
contest_cd
contest_des
clos_dt
comp_cd
Contest code.
Name and description.
Closing date.
Sponsoring company code.
comp_cd
comp_nm
address
tel_no
cont_per
Company code. (PK)
Company name.
Address.
Telephone number.
Contact person’s name.

Table : QUES_ANS Table : CON_ANS
Column Description Column Description

contest_cd
ques1
ans1
ques2
ans2
ques3
ans3
ques4
ans4
ques5
ans5
Contest code.
Question 1.
Answer 1.
Question 2.
Answer 2.
Question 3.
Answer 3.
Question 4.
Answer 4.
Question 5.
Answer 5.
con_cd
contest_cd
ans1
ans2
ans3
ans4
ans5
Contestant code.

Contest code.
Answer 1.
Answer 2.
Answer 3.
Answer 4.
Answer 5.

Table : CONTESTANT
Column Description
con_cd
con_nm
e_mail
dt_of_entry
Contestant code.
Contestant name.
E-mail address.
Date of entry.


a) Create tables CONTEST, COMPANY, QUES_ANS, CON_ANS, and CONTESTANT
b) In COMPANY table, column comp_cd, system generated sequential values like
1000,1002,1004,1006, … will be added at the time of record addition.
c) Add few required records to those tables.
Notice: PK: Primary key

Q2
Use the tables in Question 1 to state T-SQL command / query for each of the following:

a) Set the foreign key constraint for the company code in the CONTEST table.

b) Display the unique names of contestants having “hotmail.com” or “yahoo.com” as part of
their e-mail address.


c) Display the details of contests having closing date as 31st August ’2001, which have not
been attempted by any contestant.


d) Remove the details of contests from the CONTEST, QUES-ANS and CON_ANS tables,
which had closing date before 1st January ’2001.


e) Display Contestcode, contestantcode, contestantname and total no of contestant for each
contestcode. Display the total no. of contestants also for all the contests.


f) Create a view MAX_ENTRY that stores the contest details of contests for which more than
5 contestant entries have been received.


g) Display the company code, name and number of contests sponsored by the company that has
sponsored the highest number of contests.



Q3 :
Create a trigger, named trig_Del_CONTEST, which will be invoked when a contest
being deleted from the CONTEST table.
Before deletion, the contest_cd, contest_des, comp_cd, dt_of_withdraw will be
stored in a CONTEST_HIST table. At the same time it will be deleting all

corresponding records from QUES_ANS and CON_ANS tables.
CONTEST_HIST table has the structure as follows :




Table : CONTEST_HIST

Column Description


contest_cd
contest_des
comp_cd
dt_of_withdraw
Contest code.
Name and description.
Company code
Date of deletion