ORA-22905 and Cast function

Question

I am running a query with following code:
select d.acct_num, lib.fmt_money(a.amt) Total Amount
from account d, table(report.lib.expense (d.acct_num)) a
where clause.
Here:
1. Report is another schema containing packqges for reporting development.
2. lib is package name created in the report schema. It contains function such as expense.
3. expense is a function under Lib package as
function expense (p_acct number) return number is
acct_num number;
begin select xxxx into acct_num from xxx_table); return nvl(acct_num, 0);
end expense;
Then when I run this select statement, it gave me ORA-22905 error. Cause: attempt to access rows of an item whose type is not known at parse time or that is not of a nested table type. Action: use CAST to cast the item to a nested table type.
I used CAST like this:
select d.acct_num, CAST(a.amt as number ) Total Amount
from account d, table(report.lib.expense (d.acct_num)) a
where clause.
It gave me ORA-00923 From keyword not found where expected.
Please help me to find where the problem is and thank you for your help a lot.

Answer 1

citicbj wrote:
I have checked function and found that function was defined as this:
function expense (p_exp varchar2) return number
is
l_exp number;
begin
select xxx into l_exp from xxxx where clause;
return nvl(l_exp, 0);
end expense;
So this is not defined as the table of array. So I take the table off from select statement as
select d.acct_num,
to_number(a.amt) Total Amount
from account d,
report.lib.expense (d.acct_num) a
where d.acct_num = a.acct_num;
Then it return ORA-00933 SQL command not ptoperly ended. However, I couldn't see any not properly ended SQL code here. Please advise your comments.Should just be ...
select
   d.acct_num,
   report.lib.expense (d.acct_num) as "Total Amount"
   --to_number(a.amt) Total Amount
from account dNotice that i enclosed the column alias (Total Amount) in " ... that is because you can't have a column alias with spaces as you tried without doing this (the parser gets sad).
Also, you cannot use a function returning a single value like this as a nested table (at least not the way you are trying) and in your case there's no reason. You don't want to join to it, you are passing in ACCT_NUM which the function will presumably use to filter out not relevant data.
Finally, there's no reason to TO_NUMBER the function result ... it's already defined to return a number :)