Null not showing

[Hugo Nilsson]

So im very new to SQL and i have a problem with my code:

select username,fnamn,enamn,nvl(årslön,0) as årslön
from kund
where årslön < (select avg(nvl(årslön,0)) from kund);

It shows the ones i want except the null value as 0. Anyway i can fix this?

[Jj Roberts]

Hi!
I assume you are using an Oracle database. The NVL() function tests if something is null, at lets you specify a value to use instead. So

NVL('somestring', 'otherstring') 

will give you 'somestring', because it is not null. But if you tried

NVL(null, 'otherstring') 

you will get 'otherstring'.

Basically NVL() allows you to replace null with another value. Does that help?

[Hugo Nilsson]

It dosent . The thing is that the code dosent pull the information from the row where the null value is like it does with the other ones

[Paul Clapham]

where årslön < (select avg(nvl(årslön,0)) from kund)

Maybe you want

where avg(årslön,0) < (select avg(nvl(årslön,0)) from kund)