sql command not ended properly after executing the function - oracle

Question

for example I have created a table with table name 'aaa' with four columns act_num, clear_balance, available_balance, total_balance and I have inserted some values.
The function
deb_amount withdraws money from a bank account. It accepts an account
number and an amount of money as parameters. It uses the account number to
retrieve the account balance from the database, then computes the new balance. If this
new balance is less than zero then the function jumps to an error routine; otherwise,
it updates the bank account.
create or replace function deb_amount(p_act_num VARCHAR2, p_amount number )
return number as
declare
v_old_amount number;
v_new_amount number;
e_over_drawn exception;
begin
select clear_balance into v_old_amount from aaa where act_num=p_act_num;
v_new_amount:=v_old_amount-p_amount;
if v_old_amount<p_amount then
raise e_over_drawn;
else
update aaa set clear_balance=v_new_amount,available_balance=v_new_amount,total_balance=v_new_amount where act_num=p_act_num;
end if;
commit;
return clear_balance;
exception
when e_over_drawn then
rollback;
end;
it will compile, but with warnings.
If I want to execute the 'select * from deb_amount(1,100)' it show error.
sql command not ended properly.
Thank you.

Answer 1

You need to call function using dual. Ex:
select deb_amount(1,100) from dual;
or using a variable in plsql block
declare
l_return number;
begin
l_return:=deb_amount(1,100);
end;

Answer 2

It looks like you might be running several commands as a scipt, but haven't ended the function properly. The / after the function creation has to be on a line on its own, and at the start of the line:
create or replace function deb_amount(p_act_num VARCHAR2,
p_amount number)
return number as
declare
v_old_amount number;
v_new_amount number;
e_over_drawn exception;
begin
select clear_balance into v_old_amount
from aaa where act_num=p_act_num;
v_new_amount:=v_old_amount-p_amount;
if v_old_amount<p_amount then
raise e_over_drawn;
else
update aaa set clear_balance=v_new_amount,
available_balance=v_new_amount,
total_balance=v_new_amount
where act_num=p_act_num;
end if;
commit;
return clear_balance;
exception
when e_over_drawn then
rollback;
end;
/
show errors
select deb_account('1', 1) from dual;
The show errors will tell what actual compilation errors you got. It looks like it will complain about the return as you don't have a local clear_balance variable, but you can use v_new_amount instead here. You need to return something after the rollback too, or raise an exception which might be more useful.
As Manjunatha said, your query then needs to call the function properly, with the from clause referencing a table, rather than the function itself.
You have a bigger problem with the concept though; you can't call a function that does DML (insert, update, delete) from SQL, only from a PL/SQL block. Generally DML should be done from a procedure rather than a function, if it has to be done in PL/SQL at all.