DB2 Interview questions

harikrishnanrajeev · EXPERT Joined: 28 Jan 2004 Posts: 37 Location: Trivandrum

Q-1: I have the following SQL...

SELECT MIN(SALARY)
FROM TABLE.EMP
WHERE EMPNO = '1025' ;

In case there is no EMPNO '1025' then what would be the O/P

(i) NULL
(i) SQLCODE of +100

Q-2 : I have the following two queries

1. SELECT DEPTNAME, AVG(SALARY)
FROM TABLE.EMP
GROUP BY DEPTNAME;

2. SELECT DEPTNAME, SUM(SALARY)/COUNT(*)
FROM TABLE.EMP
GROUP BY DEPTNAME;

(i) The output of both the queries would be same.
(ii) The output of both the queries would not be same.
(iii) The output of both the queries may or maynot be the same.

Q-3: From the following table write down the query to count the
department numbers.

EMPNO WORKDEPT

1000 SALES
1001 ACCTS
1002 SALES
1003 ACCTS
1004 ACCTS
1005 ADMIN
1006 SALES
1007 ADMIN
1008 ADMIN
1009 MKETG
1010 SALES
1011 MKETG
1012 MKETG

SCROLL DOWN FOR ANSWER.....

Ans-1 : NULL

Ans-2 : (iii) In theory Avg means SUM divided by count but it maynot
return the same value b'cos SUM would ignore nulls
but the count function would count all the values regardless of
nulls. The AVG function just works on the numeric
arguments.

Ans-3 :

SELECT COUNT(DISTINCT WORKDEPT)
FROM TABLE.EMP;

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ksivapradeep · New User Joined: 30 Jul 2004 Posts: 95

question-1.

hi harikrishna,

according to u i tried this query

test== table name
esal==salary coumn name
eid==primary key

select min(esal) from test where eid=46

o/p: is +100 - record not found

how null comes

ksivapradeep · New User Joined: 30 Jul 2004 Posts: 95

i tried the sum/count(*) and avg but i am getting the same result can u explain how its diffrent value.i have seen in the book(cj.date) that sum and avg will work on numeric.

regards
siva pradeep