SQL Server 触发器自助抛异常并回滚事务

SQLServer触发器内对更新的数据进行判断，符合条件的操作则回滚。rollback关键字为回滚事务，raiseroor为自助生成SQL异常信息。代码如下：

CREATE TRIGGER [dbo].[tri_after_modify]
ON [dbo].[tablename]
AFTER INSERT, UPDATE, DELETE
AS
if(select COUNT(*) from deleted) > 1
begin
	rollback
	raiserror ('错误信息：一次只能修改一个。',17,1)
	return
end