PL/ SQL- WHEN / Conditional commands - oracle

Question

I am trying to increase the salary of three employees by prompting the user. The job_ids are 1, 4, and 8. I cannot seem to get my WHEN statements to work or properly interact with the datatables. Anyone have any insights?
SET SERVEROUTPUT ON
SET VERIFY OFF
accept selection prompt 'Please enter your employee ID'
DECLARE
JobNumber INT(2) := ('&selection.');
NewSalary VARCHAR2(30);
BEGIN
update emp_employee
set NewSalary = case
WHEN JobNumber = '1' THEN NewSalary := emp_employees.salary * 1.10;
WHEN JobNumber = '4' THEN NewSalary := emp_employees.salary * 1.15;
WHEN JobNumber = '8' THEN NewSalary := emp_employees.salary * 1.20;
ELSE 'Invalid ID'
END;
DBMS_OUTPUT.PUT_LINE ('Job ID '|| JobNumber || 'Salary ' || NewSalary);
END;
/

Answer 1

i think your update should be like below
update emp_employee
set NewSalary = case
WHEN JobNumber = 1 THEN emp_employees.salary * 1.10;
WHEN JobNumber = 4 THEN emp_employees.salary * 1.15;
WHEN JobNumber = 8 THEN emp_employees.salary * 1.20;
ELSE null
END;
//NewSalary is numeric field you can not assign string value invalid

Answer 2

As you didn't provide test case, I'm using Scott's schema and his EMP table. The principle is the same, though.
Have a look a this example and note the differences:
CASE you wrote is wrong; you've already said that NewSalary should be something (within the UPDATE), so you don't repeat it once again)
ELSE can't be 'Invalid ID'; you'd put a string into a NUMBER datatype column. I handled it within the IF statement - if nothing has been updated, such an employee doesn't exist.
you can't output NewSalary as you don't know it. I returned its value into a separate local variable (l_new_sal)
Also, if I were you, I'd rather create a stored procedure instead of using an anonymous PL/SQL block. If you use it for educational purposes, let it be (but you can try to convert it to a procedure, if you want).
Here you go; one example with a non-existent EMPNO, and another one for employee that exists.
SQL> set serveroutput on
SQL> set ver off
SQL> accept par_selection prompt 'Enter EMPNO: '
Enter EMPNO: 1234
SQL> declare
2 l_empno emp.empno%type := &par_selection; -- it is employee ID, not job number!
3 l_new_sal emp.sal%type;
4 l_cnt number;
5 begin
6 update emp e set
7 e.sal = case when e.deptno = 10 then e.sal * 1.1
8 when e.deptno = 20 then e.sal * 1.15
9 when e.deptno = 30 then e.sal * 1.2
10 else e.sal
11 end
12 where e.empno = l_empno
13 returning sal into l_new_sal;
14
15 l_cnt := sql%rowcount;
16
17 if l_cnt > 0 then
18 dbms_output.put_line('Employee ' || l_empno || ', new salary = ' || l_new_sal);
19 else
20 dbms_output.put_line('Nobody got new salary');
21 end if;
22 end;
23 /
Nobody got new salary
PL/SQL procedure successfully completed.
SQL> accept par_selection prompt 'Enter EMPNO: '
Enter EMPNO: 7369
SQL> /
Employee 7369, new salary = 920
PL/SQL procedure successfully completed.
SQL>