Trigger which check the current Date with the Date in the table - sql

I do not know how to compare 2 Dates in a trigger (one in the table and the current Date)
Here is my draft of the trigger:
CREATE trigger check_update
BEFORE DELETE ON customer_contract
For each row
Begin
If(date_to_cancel_contract > (<date>))
Signal sqlstate ‘45000’
Set message_text = ‘Error, not allowed to cancel contract.’
END IF
What’s wrong? How can I fix the problem?

The condition should be (provided it is SQL Server)
If(date_to_cancel_contract > dateadd(day,datediff(day,0,getdate()),0))

Related

Check future date in trigger

I want to launch a trigger if a user try to replace current date with a future date.But subquery might not allowed in trigger. How can i solve this issue? Any suggestion....
CREATE OR REPLACE TRIGGER check_join_date
BEFORE UPDATE OF join_date ON DOCTOR
FOR EACH ROW
WHEN (NEW.join_date > (SELECT CURRENT_DATE+1 FROM DUAL) )
BEGIN
RAISE_APPLICATION_ERROR(-20509,'Do not Enter Future Date..');
END check_join_date;
/
I am getting this error after running this code in Oracle.
ORA-02251: subquery not allowed here
test this
CREATE OR REPLACE TRIGGER check_join_date
BEFORE UPDATE OF join_date ON DOCTOR
FOR EACH ROW
WHEN (NEW.join_date > CURRENT_DATE+1)
BEGIN
RAISE_APPLICATION_ERROR(-20509,'Do not Enter Future Date..');
END check_join_date;
/

Oracle SQL Instead of Delete Trigger

I want to create an 'instead of delete' trigger to restrict the deletion of a row when the value entered exceeds a certain amount.
I have an Invoice table with 2 columns: Invoice(InvoiceID Number, Total Number)
I want the trigger to fire if I try to delete a row that has a stored value in Total >= 100 and prevent the deletion.
So far I have a rough sketch of what I want, but I'm not sure if the exact syntax is correct.
CREATE OR REPLACE TRIGGER IOFD_INVOICE
INSTEAD OF DELETE ON INVOICE
BEGIN
DECLARE
TTL INTEGER;
SELECT TOTAL = TTL
FROM INVOICE
IF TTL >= 100
BEGIN
RAISERROR('Record cannot be deleted.')
ROLLBACK
END
ELSE
BEGIN
DELETE FROM INVOICE
END
END;
I thought instead of triggers could be used on tables but I get the following error Message:
Error report -
ORA-25002: cannot create INSTEAD OF triggers on tables
25002. 00000 - "cannot create INSTEAD OF triggers on tables"
*Cause: Only BEFORE or AFTER triggers can be created on a table.
*Action: Change the trigger type to BEFORE or AFTER.
INSTEAD OF triggers are only applicable to views.
The logic can be accomplished by a simple
CREATE OR REPLACE TRIGGER BD_INVOICE
BEFORE DELETE ON INVOICE FOR EACH ROW
BEGIN
IF :OLD.TOTAL >= 100 THEN
RAISE_APPLICATION_ERROR(-20001,'Record cannot be deleted.');
END IF;
END;

How to user trigger to update a column comparing with system date in Oracle?

I wrote this trigger to update a certain column. The trigger I wrote is this:
CREATE TRIGGER updateotMark
BEFORE UPDATE
ON sBookBorrow
FOR EACH ROW
WHEN(SYSDATE-to_date(etime)>15)
BEGIN
UPDATE otMark = 1;
END;
/
This is the first time I use trigger, so I have no idea what went wrong. Any ideas? Thanks everyone for your answer.
UPDATE: This is what I got in the console. What did I do wrong?
UPDATE2:Now it has a error message:ERROR at line 5:
ORA-04076: invalid NEW or OLD specification
What is the data type of "etime"?
If date, you don't need to use "TO_DATE" function. ex.(SYSDATE - etime > 15)
If VARCHAR2, you need to put the format. ex. TO_DATE(etime,'YYYYMMDD')
However, use SHOW in SQLPlus will give you more information about error.
SHOW ERROR TRIGGER updateotMark;
Let try this.
CREATE OR REPLACE TRIGGER updateotMark
BEFORE UPDATE
ON sBookBorrow
FOR EACH ROW
WHEN (SYSDATE - NEW.etime > 15)
BEGIN
:NEW.otmark := 1;
END;
Just update the :new value
CREATE TRIGGER updateotMark
BEFORE UPDATE
ON sBookBorrow
FOR EACH ROW
WHEN(SYSDATE-to_date(etime)>15)
BEGIN
:new.otmark = 1;
END;

Using Sysdate in trigger

Hello guys I'm a bit of a noob when it comes to triggers so I'm just looking for some advice on how to do the follow trigger.
I have created a trigger that will throw an error message if someone was to delete a record during office hours however I would like to create another trigger that uses SYSDATE will not delete records from say today and future dates.
I was thinking of maybe using >=SYSDATE but I'm not sure if that is a valid sql statement.
CREATE OR REPLACE TRIGGER records_delete
BEFORE DELETE
ON RECORDS FOR EACH ROW
BEGIN
IF TO_CHAR(SYSDATE, 'HH24MI') NOT >= sysdat
RAISE_APPLICATION_ERROR(-20669, 'You can not delete current or future records');
END IF;
END records_delete;
Thanks, leprejohn
The problem here is that you're not referencing any of the fields of the table that you're deleting from.
If your table had a column called record_date then you could rewrite this as:
CREATE OR REPLACE TRIGGER records_delete
BEFORE DELETE
ON RECORDS FOR EACH ROW
BEGIN
IF (:old.record_date >= SYSDATE) THEN
RAISE_APPLICATION_ERROR(-20669, 'You can not delete current or future records');
END IF;
END records_delete;
The syntax :old. and :new. are how you reference the columns of the current record being acted upon by the trigger, with :old. being the prefix for inspecting the values before the trigger acts on it and :new. being for values after the trigger is done. This syntax allows you to see the values before/after the trigger updates the data, which in your case doesn't matter since you're deleting records.
If you want to disregard the hours, mins, seconds of the date fields, use this in the IF statement
trunc(:old.record_date) >= trunc(SYSDATE)
If record_date is actually stored as a string instead of a date, you would convert it to a date before comparison:
to_date(:old.record_date, 'DDMMYYYY') >= trunc(SYSDATE)
Update the format mask 'DDMMYYYY" to the format your date is actually stored in. Check the Oracle documentation for description of to_date and date format models.
Give this a shot and see if it works.

Trigger to check logic date update

Building an employee database and we want to make sure the database can't be updated incorrectly with employment end date being before the start date. We want to use a trigger to block the update, throw an error, and rollback.
I know this is wrong but this is where I am:
CREATE TRIGGER EmpLeaveWarn on Employee FOR UPDATE
AS
IF(select End_Date < Start_Date)
BEGIN
RAISERROR ('The End date must come after the Start date')
ROLLBACK TRAN
RETURN
END
GO
For Microsoft SQL Server.
Thanks in advance.
No need for a trigger, just use a constraint:
alter table EmpLeaveWarn
add constraint check_end_date check (End_Date >= Start_Date);
The easiest way to acheive this would be by using a check constraint, not a trigger:
ALTER TABLE Employee ADD CONSTRAINT Employee_Date_Check CHECK ( End_Date >= Start_Date)