How do I display the result of the procedure Oracle? - oracle

Question

In my code there is a function that displays a message on the screen. But when I start, I do not see the result.
I guess this line does not work.
UPDATE EMPLOYEES SET COMMISSION_PCT = NEWCOMMISSION WHERE LINES.COMMISSION_PCT IS NULL;
Is it so?
I'm using Oracle XE 112, I'm using a browser.
Full code
CREATE OR replace PROCEDURE Zadacha31
IS
lengthphone INTEGER;
substrcommission VARCHAR2(50);
newcommission FLOAT;
info FLOAT;
CURSOR get_data IS
SELECT *
FROM employees;
BEGIN
FOR lines IN get_data LOOP
IF lines.commission_pct IS NULL THEN
lengthphone := Length(lines.phone_number);
substrcommission := Substr(lines.phone_number, lengthphone - 1, 2);
newcommission := To_number('.'
||substrcommission);
UPDATE employees
SET commission_pct = newcommission
WHERE lines.commission_pct IS NULL;
dbms_output.Put_line(lines.commission_pct);
END IF;
END LOOP;
END;

Answer 1

Try executing set serveroutput on before you run the procedure

Answer 2

It seems that you have an error in your logic.
Consider. You execute the UPDATE only if this test is true:
IF lines.commission_pct IS NULL THEN
Your code calculates a new commission and updates all the records (hint: this is probably not what you want but is irrelevant to your question).
UPDATE employees
SET commission_pct = newcommission
WHERE lines.commission_pct IS NULL;
However, your output is displaying the unamended original value and nothing else.
dbms_output.Put_line(lines.commission_pct);
So your procuedure may well be updating and displaying something, but all it's displaying is a NULL so it looks as though nothing is occuring.
To solve this, use the new value:
dbms_output.Put_line('new commission = ' ||newcommission);
To solve the updating all records use a better where condition:
UPDATE employees e
SET e.commission_pct = newcommission
WHERE e.emp_id = lines.emp_id; -- or whatever the PK is
And why not make the output message more useful while we're at it?
dbms_output.Put_line('emp# '|| lines.emp_id||' new commission = ' ||newcommission);

Answer 3

This is how it looks like in SQL*Plus:
SQL> CREATE OR replace PROCEDURE Zadacha31
2 IS
3 lengthphone INTEGER;
4 substrcommission VARCHAR2(50);
5 newcommission FLOAT;
6 info FLOAT;
7 CURSOR get_data IS
8 SELECT *
9 FROM employees;
10 BEGIN
11 dbms_output.put_line('Procedure starts here');
12 FOR lines IN get_data LOOP
13 IF lines.commission_pct IS NULL THEN
14 dbms_output.put_line('commision_pct IS NOT NULL!');
15
16 lengthphone := Length(lines.phone_number);
17
18 substrcommission := Substr(lines.phone_number, lengthphone - 1, 2);
19
20 newcommission := To_number('.'
21 ||substrcommission);
22
23 UPDATE employees
24 SET commission_pct = newcommission
25 WHERE lines.commission_pct IS NULL;
26
27 dbms_output.Put_line(lines.commission_pct);
28 END IF;
29 END LOOP;
30 dbms_output.put_line('Procedure ends here');
31 END;
32 /
Procedure created.
SQL>
SQL> set serveroutput on
SQL>
SQL> begin
2 zadacha31;
3 end;
4 /
Procedure starts here
Procedure ends here
PL/SQL procedure successfully completed.
SQL>
It appears that the procedure finished correctly, but - nothing was displayed nor updated. Let's check why:
SQL> select count(*) from employees where commission_pct is null;
COUNT(*)
----------
0
SQL>
Does it ring a bell?
As of your environment: it looks like Apex' SQL Workshop, while data you use is contained in the HR schema. If that's so, you're right - you don't need to SET SERVEROUTPUT ON there, it is enabled by default.
Though, that wasn't your problem, but the fact that no employee has COMMISSION_PCT IS NULL.