判断触发器的类型：insert update delete

在一个触发机制包含为insert update delete的触发器内部，如何判断触发该触发器的到底是insert、delete、还是update呢？

我们可以通过如下的方式：

Insert:

IF EXISTS(SELECT 1 FROM inserted) AND NOT EXISTS(SELECT 1 FROM deleted)  

 

Update:

IF NOT EXISTS(SELECT 1 FROM inserted) AND EXISTS(SELECT 1 FROM deleted)

 

Delete:

IF EXISTS(SELECT 1 FROM inserted) AND EXISTS(SELECT 1 FROM deleted)