在日期字段中的可爲空值的存儲過程

Question

在此存儲過程中，在where條件中，如果@startDate和@EndDate值爲null，那麼如何使用COALESCE來處理它。

CREATE PROCEDURE dbo.SP_ManageLeaveSearch 

    @StartDate datetime, 
    @EndDate datetime, 

    @UserName CHAR(100), 
    @MarketID INT 

AS 
BEGIN 
    SELECT d1.UserName,c1.HouseName,c.StartDate,c.EndDate 
     FROM table1 c  
     Inner JOIN table2 d1 ON c.UserID = d1.UserID 


WHERE 
    (

     (
      (@StartDate BETWEEN StartDate AND EndDate) 
      OR 
      (@EndDate BETWEEN StartDate AND EndDate) 
      OR 
       (
       (@StartDate <= Startdate AND @EndDate>=EndDate) 
       ) 
     ) 
     AND 
     (

      d1.UserName = COALESCE(@UserName, d1.UserName) 
     ) 

) 

END 

提前告誡。

Answer 1

這應該爲你工作：

CREATE PROCEDURE dbo.ManageLeaveSearch 

    @StartDate datetime = NULL, 
    @EndDate datetime = NULL, 

    @UserName CHAR(100) = NULL, 
    @MarketID INT 

AS 
BEGIN 
    SELECT d1.UserName,c1.HouseName,c.StartDate,c.EndDate 
     FROM table1 c  
     Inner JOIN table2 d1 ON c.UserID = d1.UserID 


WHERE 
    COALESCE(@StartDate,StartDate) <= EndDate AND 
    StartDate <= COALESCE(@EndDate,EndDate) AND 
    d1.UserName = COALESCE(@UserName, d1.UserName) 

END 

注：

• 不要名存儲過程與sp_前綴 - 它是保留給Microsoft的system procedures。
• 我已經用簡單的條件來確定重疊的存在。如果範圍1在範圍2結束之前開始，則在兩個範圍之間存在重疊，和範圍2在範圍1結束之前開始。
• 我已經爲那些應該爲空的參數指定了默認值。

Answer 2

嘗試這一個 -

CREATE PROCEDURE dbo.usp_ManageLeaveSearch 

    @StartDate DATETIME, 
    @EndDate DATETIME, 

    @UserName CHAR(100), 
    @MarketID INT 

AS BEGIN 

    SELECT 
      d1.UserName 
     , c.HouseName 
     , c.StartDate 
     , c.EndDate 
    FROM dbo.table1 c  
    JOIN dbo.table2 d1 ON c.UserID = d1.UserID 
    WHERE d1.UserName = ISNULL(@UserName, d1.UserName) 
     AND (
       ISNULL(@StartDate, StartDate) BETWEEN StartDate AND EndDate 
      OR 
       ISNULL(@EndDate, EndDate) BETWEEN StartDate AND EndDate 
     ) 

END 

Answer 3

您已經過於複雜的事情。這應該適用於你，並且就我所知的查詢而言簡單。我更喜歡這種語法，因爲在我的大部分用例中，...... OR @UserName IS NULL可以在執行之前從查詢中刪除，從而實現非常簡單，快速的執行。

CREATE PROCEDURE dbo.SP_ManageLeaveSearch 

    @StartDate datetime, 
    @EndDate datetime, 

    @UserName CHAR(100), 
    @MarketID INT 

AS 
BEGIN 
SELECT d1.UserName,c1.HouseName,c.StartDate,c.EndDate 
FROM table1 c  
JOIN table2 d1 
    ON c.UserID = d1.UserID 
WHERE (@StartDate<=EndDate OR @StartDate IS NULL) 
AND (@EndDate>=StartDate OR @EndDate IS NULL) 
AND (d1.UserName = @UserName OR @UserName IS NULL) 
END