Package help

Question

I need to be able to invoke a procedure (debit_account/credit_account) from the pkg body procedure process_transactions. I am getting "Debit_account" no declared in this scope".
Package specs
create or replace package bank_transactions
is
minimum_balance number(3,2) := 100.00;
procedure enter_transaction
account_number_in in transactions.account_no%type,
transact_type_in in transactions.type%type,
amt_transact_in in transactions.amount%type
procedure process_transactions;
end;
pkg body
create or replace package body bank_transactions2 is
-- Private type declarations
--type <TypeName> is <Datatype>;
-- Private constant declarations
--<ConstantName> constant <Datatype> := <Value>;
-- Private variable declarations
new_status varchar2(70);
-- Function and procedure implementations
function <FunctionName>(<Parameter> <Datatype>) return <Datatype> is
<LocalVariable> <Datatype>;
begin
<Statement>;
return(<Result>);
end;
procedure enter_transaction
account_number_in in transactions.account_no%type,
transact_type_in in transactions.type%type,
amt_transact_in in transactions.amount%type
is
begin
insert into transactions (account_no,type,amount,time_tag)
values
(account_number_in,transact_type_in,amt_transact_in,sysdate);
end enter_transaction;
procedure process_transactions(
trans_type in out varchar2,
account_no transactions.account_no%type,
amount transactions.amount%type)
is
cursor trans_cursor(trans_type in varchar2) is
select status
from transactions
where status = 'Pending'
for update nowait;
begin
for trans in trans_cursor(trans_type)
loop
process_transactions(trans_type,account_no,amount);
end loop;
if trans_type = 'D' then debit_account(account_no,amount);
elsif trans_type = 'C' then credit_account(account_no,amount);
elsif trans_type != 'D' OR 'C' then new_status := 'Rejected';
end if;
end process_transactions;
procedure credit_account
(account_number_in in transactions.account_no%type,
amt_trans_in in transactions.amount%type)
is
begin
update transactions set amount = amount + amt_trans_in
where account_no = account_number_in;
end credit_account;
procedure debit_account
(account_no_in transactions.account_no%type,amt_trans_in in transactions.amount%type)
is
begin
update transactions set amount = amount + amt_trans_in
where account_no = account_no_in;
end debit_account;
end bank_transactions2;
/

Answer 1

Well, probably having a parameterless procedure defined in the spec and overloading it with a version with parameters would be a bit odd. How is the parameterless version supposed to know how to generate the parameters for the paramteterized version?
Overloading itself is can be a good practice if it is used appropriately. Many of the Oracle built-in functions like TO_CHAR, NVL etc, are overloaded to take parameters of different types. Personally, when I use overloaded procedures, I tend to expose them in the package spec, because they do the same thing with slightly different parameters.
For example, in one aplpication we have a table that can be uniquely accessed by one of two fields (one numeric and the other varchar2). The front-end will always have one of those two fields, depending on where it got the basic information it is using. So, I have two versions of the function defined in the package spec as:
FUNCTION get_concept(p_concept_id IN NUMBER) RETURN concept_tp;
FUNCTION get_concept(p_name IN VARCHAR2) RETURN concept_tp;The front-end knows which of the two identifiers it has, so can call the appropriate version of the funtion. In the database, a "concept" is actually a join between several tables, and both versions of the function, after doing a little set up work, call another private function get_concept_int which actually takes 3 parameters. I could have called the internal function get_concept as well, but the overloading here would, at least to me, be misleading.
HTH
John