Plsql trigger if updating
08-Apr-2020 16:23
A trigger is a special type of stored procedure that automatically executes when an event occurs in the database server.
DML triggers execute when a user tries to modify data through a data manipulation language (DML) event.
It is very important to include the INNER JOIN to the INSERTED table so that only the updated rows are affected.
Using the clause WHERE Order Status='Approved' by itself to limit the rows updated will actually result in all rows with an Order Status value of Approved being updated at the same time.
DML events are INSERT, UPDATE, or DELETE statements on a table or view.
These triggers fire when any valid event is fired, regardless of whether or not any table rows are affected. DDL triggers execute in response to a variety of data definition language (DDL) events.
The T-SQL for creating this trigger is shown below.Trigger is a PL/SQL program which can be executed automatically by the oracle server whenever an event is raised.And, PLSQL Triggers are named PL/SQL DBMS Output units that are stored in the database and these triggers can be invoked repeatedly.use MSSQLTips go create table tbl Trigger Test ( pk ID integer Identity(1,1) primary key, Order Approval Date Time datetime, Order Status varchar(20) ) insert into tbl Trigger Test values (NULL, 'Pending') insert into tbl Trigger Test values (NULL, 'Pending') insert into tbl Trigger Test values (NULL, 'Pending') select * from tbl Trigger Test go create trigger tr Trigger Test on tbl Trigger Test after update as begin set nocount on; update tbl Trigger Test set Order Approval Date Time=getdate() from tbl Trigger Test t inner join inserted i on ID=ID and i.
When you sign in to comment, IBM will provide your email, first name and last name to DISQUS.After selecting all records in the table, notice how the Order Approval Date Time for the second row does not equal the Order Approval Date Time for the first row.
