ORACLE SQL PROCEDURE WITH FOR LOOP AND IF ELSE ERROR - sql

Question

I need to replace employee id in shift table for a particular day with another employee id who hasn't any shift for a particular day.
This my tables,
CREATE TABLE EMPLOYEE
(EMPLOYEE_ID NUMBER(4) NOT NULL,
NAME VARCHAR(50),
GENDER VARCHAR(10),
BIRTH_DAY DATE,
PRIMARY KEY(EMPLOYEE_ID)
);
CREATE TABLE SHIFT
(SHIFT_ID NUMBER(4),
SHIFT_DATE DATE,
CUSTOMER_ID NUMBER(4),
SERVICE_ID NUMBER(4),
EMPLOYEE_ID NUMBER(4),
SHIFT_CHARGE FLOAT(10),
PRIMARY KEY(SHIFT_ID),
FOREIGN KEY (EMPLOYEE_ID) REFERENCES EMPLOYEE(EMPLOYEE_ID)
);
For the above purpose, I want to create a procedure. I created the procedure is below. But there is a compilation error.
CREATE OR REPLACE PROCEDURE CHANGE_SHIFT_SHEDULED
(
EMPLOYEE_ID IN SHIFT.EMPLOYEE_ID%TYPE,
SHIFT_DATE IN SHIFT.SHIFT_DATE%TYPE
)
AS
CHECK_CON BOOLEAN:=TRUE;
BEGIN
FOR SICK_EMP_SHIFT_REC IN (SELECT * FROM SHIFT WHERE SHIFT.EMPLOYEE_ID=EMPLOYEE_ID AND SHIFT.SHIFT_DATE=SHIFT_DATE)
LOOP
FOR EMP_REC IN (
SELECT e.EMPLOYEE_ID,COUNT(e.EMPLOYEE_ID)AS SHIFT_COUNT,
CASE
WHEN SHIFT_COUNT>0 THEN FALSE
ELSE TRUE
END AS SHIFT_COUNT
FROM EMPLOYEE e LEFT OUTER JOIN SHIFT s ON e.EMPLOYEE_ID=s.EMPLOYEE_ID
WHERE s.SHIFT_DATE=SHIFT_DATE
GROUP BY e.EMPLOYEE_ID)
LOOP
CHECK_CON:=EMP_REC.SHIFT_COUNT;
IF CHECK_CON THEN
UPDATE SHIFT s SET s.EMPLOYEE_ID=EMP_REC.EMPLOYEE_ID WHERE s.SHIFT_ID=SICK_EMP_SHIFT_REC.SHIFT_ID;
EXIT;
END IF;
END LOOP;
END LOOP;
END;
/
Please anyone help me to solve this issue.

Answer 1

I'm not looking at logic you applied; I hope you did it right. I just fixed errors which prevented code you wrote to compile; for example:
don't name parameters as column names; use some prefix, e.g. par_ or p_
in cursor FOR loop, you can't have two columns with same name (shift_count); one has to be changed
also, you can't use an alias in the same statement's CASE (which is what you did with shift_count)
Boolean support is somewhat strange in Oracle. For example, there's no such datatype at SQL level. Therefore, you'll have to work with strings or numbers, and then "convert" them to Boolean (e.g. line #26)
The rest is OK, I suppose.
SQL> CREATE OR REPLACE PROCEDURE change_shift_sheduled (
2 par_employee_id IN shift.employee_id%TYPE,
3 par_shift_date IN shift.shift_date%TYPE)
4 AS
5 check_con BOOLEAN := TRUE;
6 BEGIN
7 FOR sick_emp_shift_rec IN (SELECT *
8 FROM shift
9 WHERE shift.employee_id = par_employee_id
10 AND shift.shift_date = par_shift_date)
11 LOOP
12 FOR emp_rec
13 IN ( SELECT e.employee_id,
14 COUNT (e.employee_id) AS shift_count,
15 CASE
16 WHEN COUNT (e.employee_id) > 0 THEN 'FALSE'
17 ELSE 'TRUE'
18 END
19 AS shift_count_case
20 FROM employee e
21 LEFT OUTER JOIN shift s ON e.employee_id = s.employee_id
22 WHERE s.shift_date = par_shift_date
23 GROUP BY e.employee_id)
24 LOOP
25 check_con :=
26 CASE
27 WHEN emp_rec.shift_count_case = 'FALSE' THEN FALSE
28 ELSE TRUE
29 END;
30
31 IF check_con
32 THEN
33 UPDATE shift s
34 SET s.employee_id = emp_rec.employee_id
35 WHERE s.shift_id = sick_emp_shift_rec.shift_id;
36
37 EXIT;
38 END IF;
39 END LOOP;
40 END LOOP;
41 END;
42 /
Procedure created.
SQL>