Whenever database is modified then triggers are fired based on the event set. Two logical tables are created when triggers are fired.
1. Inserted
2. Deleted
Types of triggers:
1. Insert trigger
2. Update trigger
3. Delete trigger
Let’s take a look and update trigger:
Column level update : Update trigger updates when any column is updated.
Table level update: Any value in table is modified.
Example Query:
Create trigger insert on <table name> for update as
if(select <value> from inserted)> 10
begin
print ‘<value> should be less than 10‘
rollback trans
end
Now let’s take a look at the query for delete trigger:
Example Query:
create trigger insert on <tablename> for delete as
if(select count(*) from delete)>1
begin
print ‘you can delete only 1 record’
rollback trans
end