Example of SQL Server trigger determining whether to insert, delete, or modify

Create trigger [updatetest] on [DBO]. [test]
For insert, update, delete
As
Begin
Declare
@ Isinsert bit,
@ Isupdate bit,
@ Isdelete bit
If exists (select 1 from inserted) and not exists (select 1 from deleted)
Set @ isinsert = 1
Else
Set @ isinsert = 0
 
If exists (select 1 from inserted) and exists (select 1 from deleted)
Set @ isupdate = 1
Else
Set @ isupdate = 0
 
If not exists (select 1 from inserted) and exists (select 1 from deleted)
Set @ isdelete = 1
Else
Set @ isdelete = 0
 
If (@ isupdate = 1)
Print 'updated'
If (@ isinsert = 1)
Print 'insert'
If (@ isdelete = 1)
Print 'delete'
 
End

 
 
 
Inserted, deleted:

This is two virtual tables. Inserted stores the tables that are affected by the insert or update operations. Deleted stores the tables that are affected by the delete or update operations.