[SQL] The association in the MSSQL UPDATE statement

Update all the title in the TableA table with the TitleName in the TableB if there is a corresponding relationship in the TableB

Update  as a Set = (Selectfrom aswhere=b.xid)

The above notation cannot be performed in MSSQL, so

We can use a function-disguised script

incoming parameters are the same

Update TableA Set =fn_getxtitle (ID)

Fn_getxtitle

ALTER FUNCTION [dbo].[Fn_getxtitle](  @id NVARCHAR( -)) RETURNS  NVARCHAR( -) asBEGINDeclare @title nvarchar( -)    Set @title =SelectB.titlename fromTableB asBwhereB.xid=@idRETURN @titleEnd

incoming parameters are different

--Create FUNCTION function

Create FUNCTION [dbo].[Fn_getdatafromoldve](  @OLDVE NVARCHAR( -)    ,@Type NVARCHAR( -) ) RETURNS  NVARCHAR( -) asBEGINDeclare @BO_ID nvarchar( -)Declare @NEWVE nvarchar( -)Declare @PjtNO_X nvarchar( -)IF @TYPE ='M'    BEGIN  Set @NEWVE =(Select Top 1Newve from [XXXX].[dbo].[mig_mapping1] whereOldve=@OLDVE  andFIELDNAME='Pspix')  if @NEWVE  is  not NULL  begin   Set @BO_ID =(Select Top 1bo_id from [XXXX].[dbo].[Mig_order_base] WHEREorder_id=@NEWVE)   if @BO_ID  is  not NULL    begin    RETURN @BO_ID   End    Else   begin    RETURN @OLDVE   End        End  Else   begin    RETURN @OLDVE   End  ENDIF @TYPE ='P'   BEGIN  Set @NEWVE =(Select Top 1Newve from [XXXX].[dbo].[mig_mapping1] whereOldve=@OLDVE  andFIELDNAME='Pspid')  if @NEWVE  is  not NULL    begin    RETURN @NEWVE   End    Else   begin    RETURN @OLDVE   End       ENDIF @TYPE ='PX'   BEGIN  Set @PjtNO_X =(Select Top 1Newve from [XXXX].[dbo].[mig_mapping1] whereOldve=@OLDVE  andFIELDNAME='Pspix')      if @PjtNO_X  is  not NULL    begin    RETURN @PjtNO_X   End    Else   begin    RETURN @OLDVE   End      END  RETURN @OLDVEEND

--Executed script

 update  [   ". [ "  . [ tb_prjmethod   [ pjtno   [ dbo  ] . [ ]  (pjtno, " p   ' ) 

[SQL] The association in the MSSQL UPDATE statement