触发器

Question

Create Trigger CurrentEventTrigger On B
For Insert
AS
    Begin
        
        Insert into A        
                  (
            c1,
            c2,
            c3,
            c4
        )
        Select 
            b1，
            b2, 
            b3, 
            b4
        from inserted --這樣
    End    

Answer 1

Create Trigger CurrentEventTrigger On B
For Insert
AS
  if not exists(select 1 from A,inserted B where A.c1=B.b1 and A.c2=B.b2 and A.c3=B.b3 and A.c4=B.b4)  
  Begin        
        Insert into A        
                  (
            c1,
            c2,
            c3,
            c4
        )
        Select 
            b1，
            b2, 
            b3, 
            b4
        from inserted
    End    

Answer 2

CREATE TRIGGER CurrentEventTrigger ON B
FOR INSERT
AS
    BEGIN
        INSERT INTO A (c1,c2,c3,c4)
        SELECT b1,b2,b3,b4
        FROM INSERTED
    END