Sql-Server触发器，根据条件匹配另一个表中的字段

USE [CDM]
GO
/****** Object:  Trigger [dbo].[UpdateAkisFlight]    Script Date: 2018/6/14 16:43:29 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER TRIGGER [dbo].[UpdateAkisFlight]
   ON  [dbo].[FlightWarnTime]
   FOR INSERT,DELETE
AS
BEGIN
if(exists(select  from inserted) and not exists(select  from deleted))
    begin
      declare @TwoCode nvarchar(),@FlightNum  nvarchar(),@ThreeCode  nvarchar(),@Etd datetime,@FlightId  int,@Calsign  nvarchar(),@ID int
       select @TwoCode=TwoCode,@FlightNum=FlightNumber,@Etd = Etd,@ID = Id from inserted
       select @ThreeCode=Code3  from Company  with(nolock)  where Code2=@TwoCode
       if @ThreeCode is not null
           begin
             set @Calsign=@ThreeCode+@FlightNum
             if @FlightNum is not null
                begin
                   update [dbo].[FlightWarnTime] set Calsign=@Calsign where Id=@ID
                end
             if @Etd is not null
               begin
                 select  @FlightId=FlightId from [AKIS].[dbo].[ValidFlight]  with(nolock)  where Calsign=@Calsign  and  ABS(DATEDIFF(MINUTE,Etd,@Etd)) <=  and DepAddrName='ZHCC'
               end
             if @FlightId is not null
               begin
                  update [dbo].[FlightWarnTime] set AkisFlightId=@FlightId where Id=@ID
               end
           end
    end
END