小编jdi*_*ids的帖子

This is a simple one but I can't seem to figure it out.

I have two parameters, 1 and 2. If one parameter is passed a null value, use the other parameter in there WHERE clause.

Ex:

SELECT ...
 WHERE CASE
    WHEN @Parameter1 IS NULL
    THEN Field2 = @Parameter2
    WHEN @Parameter2 IS NULL
    THEN Field1 = @Parameter1
  END

I know this is something simple or maybe I'm using my logic wrong. Any help or direction is appreciated.

正如标题所述，我有一个递归 CTE，当我更改 WHERE 子句中的运算符时，即使只有两行数据，它也会爆炸。

CREATE TABLE #Recursion
(Parent varchar(10), Child varchar(10), TopDate datetime)


INSERT INTO #Recursion (Parent, Child, TopDate)
VALUES
('00003137', '00003137', '2018-08-31'),
('04536347', '00003137', '2017-02-28'),
('05458040', '05458040', '9999-12-31'),
('00269705',' 05458040',' 9999-12-31')

;WITH 
Parent AS
  ( SELECT parent
     , child
     , 1 as sort
     , TopDate
 FROM #Recursion 
WHERE parent = child
 UNION ALL
   SELECT s.parent
        , d.child
        , d.sort + 1
        , s.TopDate
 FROM Parent as d
 JOIN #Recursion s
   ON s.child= d.parent
WHERE s.TopDate < d.TopDate
)

  SELECT …