getting error while inserting values into table? - sql

Question

Table structure is
Name Null Type
------------- ---- ------------
T_NO NUMBER
T_NAME VARCHAR2(10)
ENTERING_TIME TIMESTAMP(6)
LEAVING_TIME TIMESTAMP(6)
TO_DATE DATE
Trigger
create or replace trigger t4
before insert
on t4
for each row
declare
d_entering_time timestamp(6):=to_char('09:00:00AM','HH12:MM:SSAM');
begin
if (:new.entering_time <= d_entering_time) then
raise_application_error
(-20002,'Date of joining cannot be after system date.');
end if;
end;
and my inserting query
insert INTO t3 (entering_time) values ( TO_date('8:31:51AM','HH:MI:SSAM'))
I am getting the following error:
SQL Error: ORA-06502: PL/SQL: numeric or value error: character to number conversion error
ORA-06512: at "SYSTEM.T3", line 2
ORA-04088: error during execution of trigger 'SYSTEM.T3'
06502. 00000 - "PL/SQL: numeric or value error%s"
*Cause:
*Action:
Can any one suggest me where error occuring?

Answer 1

Try this:
CREATE OR REPLACE TRIGGER T4
BEFORE INSERT
ON T3
FOR EACH ROW
DECLARE
SSSSS_ENTERING_TIME NUMBER := 32400;
BEGIN
IF ( TO_NUMBER ( TO_CHAR ( :NEW.ENTERING_TIME,
'SSSSS' ) ) <= SSSSS_ENTERING_TIME )
THEN
RAISE_APPLICATION_ERROR (
-20002,
'Date of joining cannot be after system date.' );
END IF;
END;
INSERT INTO
T3 ( ENTERING_TIME )
VALUES
( TO_TIMESTAMP ( '01/01/2010 8:31:51AM',
'DD/MM/RR HH:MI:SSAM.FF' ) );
Note: I have extracted the total seconds from the time part and converted to a number for comparing. Hence I used 32400 seconds which is nothing but the actual 9 AM.
In Oracle we can turn dates into numbers and apply arithmetic to them in a variety of ways.
Hence to_char(some_date, 'SSSSS') gives us its time element as the number of seconds since midnight.

Answer 2

It looks like there is some errors in your code,
You are trying to store a string literal into to timestamp variable.
d_entering_time timestamp(6):=to_char('09:00:00AM','HH12:MM:SSAM');
It's HH12:MI:SSAM, not HH12:MM:SSAM, MI is for minute and MM is for month.
You can try like this,
CREATE OR REPLACE TRIGGER t4
BEFORE INSERT ON t3 FOR EACH ROW
DECLARE
d_entering_time TIMESTAMP :=to_timestamp('09:00:00AM','HH12:MI:SSAM.FF');
BEGIN
IF (:NEW.entering_time <= d_entering_time) THEN
raise_application_error (-20002,'Date of joining cannot be after system date.');
END IF;
END;
Insert query,
INSERT INTO t3 (entering_time) VALUES ( to_timestamp('8:31:51AM','HH:MI:SSAM.FF'));