Hi everyone, trying to call an oracle function in ksh script sql part

Question

I am trying to call an oracle function in ksh script in a select statement.

Function:

Location(p1 in varchar2, p2, in varchar2)
Return number
Is
S number;
Begin
If p1= p and p2=c
Then s=x;
Else s=y;
Return s;
End;

Ksh script:

$-(sqlplus......

Select 'product|customer|location' from dual;
Select product||customer||location(product, customer) from t1;
Exit;
End

How can we do this? The function us running fine in sql script. I just want to know how I can run the function in sql part of ksh script. Apart from this, i am also running another simple select query which is executing fine.