Learning SQL in Free Time - sql

Question

So i have the following table
EMPNO ENAME DEPTN JOB HIREDDATE SALARY
111 Narayan R22 Electrical 26-DEC-99 5000
108 Horen P69 PWD 10-DEC-95 10000
130 Roy A13 Security 15-SEP-01 25000
420 Roy D12 IT 15-SEP-99 2500
100 Allu A13 Security 26-JAN-15 15000
With datatypes
EMPNO NOT NULL NUMBER(38),
ENAME NOT NULL VARCHAR2(20),
DEPTNO VARCHAR2(5),
JOB VARCHAR2(20),
HIREDDATE DATE,
SALARY NUMBER(38)
I want to try to create a stored procedure
a) Changing the hire date of any employee.
b) Performing DML commands (Insert, Update and Delete)
c) Multiplying two numbers
I tried to use this code
CREATE PROCEDURE ChangeHired #EmpNo int, #Hired date
AS
ALTER TABLE Employee01 MODIFY HireDate = #Hired WHERE EmpNo = #EmpNo
GO;
But it doesn't work in Oracle 10g. Need some help.
Edit: UPDATE Employee01 SET HireDate = #Hired WHERE EmpNo = #EmpNo should be used that was a mistake from my side but still the code is not executed.

Answer 1

Please use below query,
update Employee01 set HireDate = #Hired WHERE EmpNo = #EmpNo
You have just created the procedure, to make it work you have to call it, Call the procedure using,
execute procedure_name(parameter1, parameter2);
Alter statement should be used only when modifying your structure of the table. While working with data, please use only DML's.

Answer 2

Syntax you used (or Jim suggested) isn't Oracle. Should be something like this (including that "multiplying" example you asked for):
Sample data (only minimum columns needed for the procedure to work):
SQL> alter session set nls_date_format = 'dd.mm.yyyy';
Session altered.
SQL> select * From employee1;
EMPNO HIREDDATE
---------- ----------
111 08.06.2020
Procedure:
SQL> create or replace procedure changehired(par_empno in int, par_hired in date)
2 is
3 a number := 2;
4 b number := 3;
5 result number;
6 begin
7 update employee1 set
8 hireddate = par_hired
9 where empno = par_empno;
10
11 result := a * b;
12 dbms_output.put_line(a || ' * '|| b || ' = ' || result);
13 end;
14 /
Procedure created.
Testing: once the procedure is created, you have to execute it. In order to see result of dbms_output.put_line, enable serveroutput in tool you use (for SQL*Plus or SQL Developer, execute set serveroutput on).
SQL> set serveroutput on;
SQL> begin
2 changehired(111, date '2020-06-08');
3 end;
4 /
2 * 3 = 6
PL/SQL procedure successfully completed.
SQL> select * from employee1;
EMPNO HIREDDATE
---------- ----------
111 08.06.2020
SQL>