PL SQL Package with Procedure, PLS-00323: subprogram or cursor - database

Question

Please help me. I am new to PL SQL. I want to Display On Screen all these details
Customer.customerNo, Customer.customerName, Customer.custBalance, customerOrder.orderDate, customerOrder.orderNo
from 2 tables [Customer, CustomerOrder]. Using the only Package with Procedure. Please help me how can I create such a package?
create or replace package my_pkg as
Procedure getAllOrders2(customer_id IN varchar2);
end my_pkg;
/
create or replace package body my_pkg as
Procedure getAllOrders2(customer_id IN varchar2) is
begin
dbms_output.put_line('customer_id is: '||customer_id );
end getAllOrders2;
end my_pkg;
/
Output Should be:
Customer Number, Customer Name, Order Number, Order Date, Customer Balance
Here is the output of all tables

Answer 1

One option is to use a cursor FOR loop (why? Because customer can have more than a single order, and - if you use a single select statement - you might get the too_many_rows error so you'd have to select into a collection or - as in my example - use a loop.
SQL> create or replace procedure getallorders2 (par_customer_id in customer.customerno%type)
2 is
3 begin
4 for cur_r in (select c.customerno,
5 c.customername,
6 c.custbalance,
7 o.orderdate,
8 o.orderno
9 from customer c join customerorder o
10 on c.customerno = o.customerno
11 where c.customerno = par_customer_id
12 )
13 loop
14 dbms_output.put_line
15 (cur_r.customerno ||', '||
16 cur_r.customername ||', '||
17 cur_r.custbalance ||', '||
18 cur_r.orderno ||', '||
19 to_char(cur_r.orderdate, 'dd.mm.yyyy')
20 );
21 end loop;
22 end;
23 /
Procedure created.
Testing:
SQL> set serveroutput on;
SQL> begin
2 getallorders2('A101');
3 end;
4 /
A101, basant, 32000, O101, 04.02.2021
PL/SQL procedure successfully completed.
SQL>
Now that you know how, move that code into a package body.