How put a condition in the where clause in the procedure? - oracle

Question

I want to put a condition in the where clause according to the null condition of the parameter in the procedure. But the procedure I made has some problem. There's problem is in IF clause.
How I can put a condition in the where clause in the procedure?
CREATE OR REPLACE PROCEDURE SP_PROCEDURE(START_DATE, END_DATE)
IS
START_DATE DATE;
END_DATE DATE;
BEGIN
START_DATE := TO_DATE(START_DATE, 'YYYYMMDD');
END_DATE := TO_DATE(END_DATE, 'YYYYMMDD');
INSERT INTO USER
(
USR_KEY,
USR_NAME
)
SELECT
USR_KEY,
USR_NAME
FROM
USER
WHERE
1 = 1
IF START_DATE THEN --I think there's problem here..
AND USR_CRT_DATE >= START_DATE
END IF;
COMMIT;
EXCEPTION
WHEN OTHERS THEN
ROLLBACK;
END;

Answer 1

If I'm reading your requirements correctly, this should do the trick
CREATE OR REPLACE PROCEDURE SP_PROCEDURE(START_DATE, END_DATE)
IS
START_DATE DATE;
END_DATE DATE;
BEGIN
START_DATE := TO_DATE(START_DATE, 'YYYYMMDD');
END_DATE := TO_DATE(END_DATE, 'YYYYMMDD');
INSERT INTO USER
(
USR_KEY,
USR_NAME
)
SELECT
USR_KEY,
USR_NAME
FROM
USER
WHERE (USR_CRT_DATE >= START_DATE
or START_DATE is null );
COMMIT;
END;
You don't need that exception handler. By default if a PL/SQL unit fails, it will rollback changes to the commencement point of the procedure.

Answer 2

You are missing the data types in the signature of the procedure.
Never use TO_DATE on a value that is already a DATE (as it will implicitly convert it from the date to a string and then back to a date and is likely to introduce errors in the conversion). If you want to remove the time component of a date then use TRUNC instead of trying to use TO_DATE.
It is bad practice to use COMMIT in a procedure as it does not allow you to chain multiple procedures together and then if one fails you can ROLLBACK them all; instead you should COMMIT in the transaction that calls the procedure.
USER is a keyword and cannot be used as an unquoted identifier; if you try you will get the exception ORA-00903: invalid table name. Best practice would be to name the table something that is not a keyword but you could also use quoted identifiers (which is not considered best practice).
CREATE OR REPLACE PROCEDURE SP_PROCEDURE(
START_DATE IN DATE,
END_DATE IN DATE
)
IS
BEGIN
INSERT INTO "USER" (
USR_KEY,
USR_NAME
)
SELECT USR_KEY,
USR_NAME
FROM "USER"
WHERE (START_DATE IS NULL OR USR_CRT_DATE >= TRUNC(START_DATE));
END;
/
fiddle