SQL server 触发器的使用

 1 --1.查看建立于某个表的触发器
SELECT * FROM SYSOBJECTS WHERE XTYPE='TR' AND parent_obj = OBJECT_ID('表名')

--2.查看数据库中所有的触发器
--use 数据库名
--go
--select * from sysobjects where xtype='TR'
--sysobjects 保存着数据库的对象，其中 xtype 为 TR 的记录即为触发器对象。在 name 一列，我们可以看到触发器名称。


--3.sp_helptext 查看触发器内容
--use 数据库名
--go
--exec sp_helptext '触发器名称'

--4.删除触发器
--drop trigger 触发器名称

--5.触发器的使用
--5.1、添加
go
create trigger eqadd 
on [RT.Face].[dbo].[Equipment]
after insert
as
begin
  declare @DeviceNo varchar(50),@ProjectId int,@DeviceType int
  select @DeviceNo=DeviceNo,@ProjectId=ProjectId,@DeviceType=DeviceType from inserted
  if(@DeviceType=2)
  begin
      insert into [RT.Face].[dbo].[CameraConfiguration](ProjectId, DeviceNo, Retrograde, RedLight, AbnormalDriving, SpeedMonitoring, 
      OpportunityDominates, LicensePlateRestrictions, TurnAround, EmergencyLanesOccupancy, ITime, uptType)values(@ProjectId,@DeviceNo,1,1,1,1,1,1,1,1,getdate(),0);
  end
end

--5.2  修改
go
create trigger equpt 
on [RT.Face].[dbo].[Equipment]
after update
as
begin
  declare @DeviceNo varchar(50),@ProjectId int,@DeviceType int,@DeviceNos varchar(50),@DeviceTypes int,@counts int
  select @DeviceNo=DeviceNo,@ProjectId=ProjectId,@DeviceType=DeviceType from inserted
  select @DeviceNos=DeviceNo,@DeviceTypes=DeviceType from deleted
  if(@DeviceNo!=@DeviceNos and @DeviceTypes=2)
  begin
        update [RT.Face].[dbo].[CameraConfiguration] set DeviceNo=@DeviceNo,ProjectId=@ProjectId where DeviceNo=@DeviceNos;
  end
  select @counts=count(*) from [RT.Face].[dbo].[CameraConfiguration] where DeviceNo=@DeviceNo
  if(@counts<1)
  begin
        if(@DeviceType=2)
        begin
            insert into [RT.Face].[dbo].[CameraConfiguration](ProjectId, DeviceNo, Retrograde, RedLight, AbnormalDriving, SpeedMonitoring, 
             OpportunityDominates, LicensePlateRestrictions, TurnAround, EmergencyLanesOccupancy, ITime, uptType)values(@ProjectId,@DeviceNo,1,1,1,1,1,1,1,1,getdate(),0);
        end
        else
        begin
            delete from [RT.Face].[dbo].[CameraConfiguration] where DeviceNo=@DeviceNo;
        end
  end
  
end


--5.3  删除
go
create trigger eqdel 
on [RT.Face].[dbo].[Equipment]
after delete
as
begin
  declare @DeviceNo varchar(50),@DeviceType int
  select @DeviceNo=DeviceNo,@DeviceType=DeviceType from deleted
  if(@DeviceType=2)
  begin
        delete from [RT.Face].[dbo].[CameraConfiguration] where [DeviceNo]=@DeviceNo
  end
end