IFNULL

The IFNULL function returns the first nonnull expression.

Read syntax diagram
>>-IFNULL(expression,expression)-------------------------------><

The schema is SYSIBM.

IFNULL is identical to the COALESCE scalar function except that IFNULL is limited to two arguments instead of multiple arguments. For a description, see COALESCE.

Example: For all the rows in sample table DSN8A10.EMP, select the employee number and salary. If the salary is missing (is null), have the value 0 returned. 
   SELECT EMPNO, IFNULL(SALARY,0)
     FROM DSN8A10.EMP;