100 Common DB2 Questions Asked in Interviews

Gautam512

Hi All,

Here is the attached document of 100 frequently asked DB2 interview questions.

Thanks,
Gau

parikshit123 · Active User Joined: 01 Jul 2005 Posts: 279 Location: India

Hi,
Your document is really nice.

It seems that the answer to quetion # 20 seems to be wrong.

Rajen · Active User Joined: 05 May 2005 Posts: 61

Hi Parikshit,
Really nice observation.

I guess this answer is partly right.

We have query as below.

SELECT SUM(SALARY)
FROM EMP
WHERE QUAL='MSC';

Now this will return NULL only if
1)All the rows fetched by Where condition has value of column SALARY equal to NULL. For example if the result table contains 10 rows and all these 10 rows are having SALARY value NULL then the above query will return NULL

2) Now if any of the rows in the result table is having ZERO (0) value then it will return ZERO.

So its like NULL + NULL + NULL + NULL = NULL and
NULL + NULL + NULL + 0 = 0.

Please correct me if i am wrong.

Thanks,
Rajen.

sachin_star3 · Active User Joined: 30 Sep 2006 Posts: 53 Location: pune

hi
sorry you are wronge
In coloumn function when no row written ie. in where clause condition not satishfied then output is NULL.(NOT RELATION ABOUT THE COLOUMN IS NULL OR NOT) EXCEPT COUNT FUNCTION,IN COUNT WHEN NO ROW FECHED i.e conition in where clause is not satishfied ,THEN ANS IS ZERO

AND ABOUT NULL COLOUMN :- ALL COLOUMNS FUNCTION NOT COUNT THE ROW WHERE THERE IS NULL , BUT EXCEPT COUNT(*) FUNCTIONS ALSO COUNT THE NULL COLOUMN BECAUSE IT IS ACTE4D ON ROW NOT COLOUMN

FROM-SACHIN
PUNE

nitin-mainframe · New User Joined: 01 Mar 2007 Posts: 4 Location: pune

dick scherrer · Posted: Fri Apr 20, 2007 7:27 pm Post subject:

Hello,

The attachment is in the initial post. If you right-click on "Download" you may open it or save it.

ajay_diaz · New User Joined: 12 Sep 2005 Posts: 22

Question 43 is:
How do you simulate the EXPLAIN of an embedded SQL statement in SPUFI/QMF? Give an example with a host variable in WHERE clause.)
A. Use a question mark in place of a host variable ( or an unknown value ). e.g.
SELECT EMP_NAME
FROM EMP
WHERE EMP_SALARY > ?

I tried doing that but I am getting error message
Invalid use of "?".

Can anybody please help?

Thanks
Ajay