Need help in decode statement to check condition

Question

Hi All,
I have table emp with below structure
empno
work_phone_no
Home_phone
cell_phone
For the employee if work_phone & Home Phone is null then in place of work_phone we need to send the cell_phone number.
How to use the decode statement in this scenario to test for Home_phone
condition in the select statement.
select DECODE (work_phone_no,
null, cell_phone_no,office_phone_no )
from emp
Thanks

Answer 1

Hi,
Given the data you posted:
empno work_phone_no home_phone_no cell_phone_no
1     null          80032108556   8003210855
2     null          null          8003210000 and your requirement is
"If work & Home nunbers are null then display cellhone number in place of workphone number "
, then, as John said, you do not want the results you posted. You want:
1 null       80032108556
2 8003210000 null That is, on the first row, where empno=1, the work_phone_no is NULL because the home_phone_no is NOT NULL, and cell_phone_no is only to be shown when both of the other phone numbers are missing.
To get the results above, use CASE:
SELECT  empno
,       CASE
            WHEN  work_phone_no IS NULL
              AND home_phone_no IS NULL
            THEN cell_phone_no
            ELSE work_phone_no
        END  AS work_phone_no
,       home_phone_no
FROM    ...If you really do want the results you posted, then, as John said, use NVL.