SQL Select statement returning NULL

Question

I have the following CASE statement in my SELECT clause:

       CASE HHHCRIN
       WHEN 'Y' THEN HHHINVN ELSE 'N/A'
       END AS "Credit Memo Document Number",

Can someone tell me why I get a NULL rather than N/A?

Answer 1

from the comments

HHHCRIN is 'Y' or 'N', HHHINVN is defined as S 7,0 it is an invoice number.

You can't return a string, be it blanks or 'N/A' when the return column is numeric.

Since Db2 can't implicitly convert 'N/A' to a number, you get null.

Try returning all strings...

   CASE HHHCRIN
   WHEN 'Y' THEN char(HHHINVN) ELSE 'N/A'
   END AS "Credit Memo Document Number",