What are the rules for folloiwng 2 function scenarios,

1) we can not write two or more functions in same select statement?
2) we can not use nested functions like sum(avg(salary)) group by
employee_id?

Please give link explaining in detail for this will be more helpful.
If you having any docs for this then mail it to denisvenis@gmail.com


Thanks,
Denis.

It probably depends on which functions you are talking about. You can certainly use 2 or more functions, or nested functions, for many of the functions, but there may limitations on the ones that require some arithmetic.

What does "we can not ..." mean? Do you get an error message or other results than what you expect?

An expression like "SUM(AVG(salary))" is syntactically possible, of course. But the SUM() is not needed because it won't change the result at all. So it really depends on what you want to achieve.

An aggregate function must not include another aggregate function. SQLCODE = -112