SQL Server：根据其他表值填充列

Question

I have two tables: TableA

ID AID  BID   Status
1  100  1000
2  101  1001
3  102  1000

and so on...

TableB

AID BID
100  1000
101  1008
107  1001

Now I want to populate tableA, status with 'FAIL' if: 1.for AID in tableA, its corresponding BID should be equal to same values of tableB 2. If corresponding BID is not same in tableB, make sure it dont exist in tableB means BID is a new value which dont exist in TableB

Example: TableA, AID = 100 BID = 1000. now this AID = 100 should be looked into tableB; in tableB for AID 100; BID = 1000 so its not a fail.

1. Therefore for AID 100, BID should be either 1000 (from tableB) or any other new value that do not exist in TableB.BID irrespective of AID.

A.AID = 101 BID=1001 but this BID value exist for B.AID = 107 so its a fail. Expected result:

    ID AID  BID   Status
    1  100  1000  NULL
    2  101  1001  FAIL
    3  102  1000  FAIL

Thanks

Answer 1

Just stumbled on this un-answered question while looking at something else. These two queries in the same order seems to be a simple answer:

  update TableA
    set Status = 'F'

    update TableA T
    Set Status = 'N'
    where T.ID in (Select A.ID from TableA A, TableB B
                                    where A.AID = B.AID and A.BID = B.BID)

Answer 2

Update TableA
Set Status =   Case
               When Exists (
                           Select 1
                           From TableB
                           Where TableB.AID = TableA.AID
                               And TableB.BID = TableA.BID
                           ) Then Null
                When Not Exists (
                                Select 1
                                From TableB
                                Where TableB.BID = TableA.BID
                                ) Then Null
                Else 'FAIL'
                End

Answer 3

I'm using bigint as datatype because I simply don't know what king of type is there...
This should help anyway:

DECLARE @ID bigint, @BID bigint

DECLARE CURSOR_CHECK CURSOR FOR
SELECT ID, BID FROM tableA

OPEN CURSOR_CHECK
FETCH NEXT FROM CURSOR_CHECK INTO @ID, @BID

BEGIN TRANSACTION

WHILE @@FETCH_STATUS == 0
BEGIN

   IF ((SELECT COUNT(*) FROM tableB WHERE BID = @BID) > 1)
      UPDATE tableA SET status = 'FAIL' WHERE id = @ID

   FETCH NEXT FROM CURSOR_CHECK INTO @ID, @BID

END

COMMIT