多次使用一個CTE

Question

我有這個，我在設定的總數上得到一個錯誤。 爲什麼我不能多次訪問cte？

ALTER PROCEDURE [dbo].[GetLeaguePlayers] 
(
    @idleague int, 
    @pageNumber int, 
    @pageSize int, 
    @total int OUTPUT 
) 
AS 
WITH CTEPlayers AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY p.Name) AS RowNumber, p.Id, p.Name, t.Name AS Team 
    FROM Players p INNER JOIN Teams t ON p.IdTeam=t.Id INNER JOIN Leagues l ON l.Id=t.IdLeague 
    WHERE l.Id=@idleague 
) 
SELECT Id, Name 
FROM CTEPlayers c 
WHERE RowNumber>@pageSize*(@pageNumber-1) AND RowNumber<@pageSize*@pageNumber; 
SET @total = (SELECT COUNT(*) FROM CTEPlayers) 

Answer 1

A CTE基本上是一次性視圖。它只會持續一條語句，然後自動消失。

選項包括：

• 重新定義CTE第二次。這很簡單，只需從WITH...到定義的末尾複製粘貼到SET之前即可。

• 把你的結果到#temp表或@table可變

• 結果物化到一個真正的表，並說明

• 阿爾特略有隻是SELECT COUNT從CTE：

。

SELECT @total = COUNT(*) 
FROM Players p 
INNER JOIN Teams t 
    ON p.IdTeam=t.Id 
INNER JOIN Leagues l 
    ON l.Id=t.IdLeague 
WHERE l.Id=@idleague 

Answer 2

根據定義，CTE僅對一個語句有效。

您可以創建一個inline table-valued function，然後根據需要隨時使用它。內聯函數完成名稱的功能。它的查詢成爲使用它的查詢的一部分（與單獨執行並用作行集的非內聯函數相比）。

Answer 3

在這種情況下，我用這個：

ALTER PROCEDURE [dbo].[GetLeaguePlayers] 
(
@idleague int, 
@pageNumber int, 
@pageSize int, 
@total int OUTPUT 
) 
AS 

WITH CTEPlayers AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY p.Name) AS RowNumber,  
     COUNT(1) OVER() AS RecordCount, 
    p.Id, p.Name, 
    t.Name AS Team 
    FROM Players p 
     INNER JOIN Teams t ON p.IdTeam=t.Id 
     INNER JOIN Leagues l ON l.Id=t.IdLeague 
    WHERE l.Id=@idleague 
) 

SELECT RowNumber, 
    CAST(CEILING(CAST(RecordCount AS FLOAT)/CAST(@pageSize AS FLOAT)) AS INT) PageCount, 
    RecordCount, 
    Id, 
    Name 
FROM CTEPlayers c 
WHERE RowNumber > @pageSize*(@pageNumber-1) AND RowNumber < @pageSize*@pageNumber; 

Answer 4

上述答案都是正確的。你可以執行一次CTE，實現你想要的結果。這裏是查詢

ALTER PROCEDURE [dbo].[GetLeaguePlayers] 
(
    @idleague int, 
    @pageNumber int, 
    @pageSize int, 
    @total int OUTPUT 
) 
AS 
WITH CTEPlayers AS 
(
    SELECT p.Id, p.Name, t.Name AS Team 
    FROM Players p INNER JOIN Teams t ON p.IdTeam=t.Id INNER JOIN Leagues l ON l.Id=t.IdLeague 
    WHERE l.Id=@idleague 
), 
TotalCount AS 
(
SELECT COUNT(*) AS Total FROM CTEPlayers 
), 
Final_Result AS 
(
SELECT ROW_NUMBER() OVER (ORDER BY p.Name) AS RowNumber, p.Id, p.Name, t.Name AS Team, 
    (SELECT Total FROM TotalCount) AS Total 
    FROM CTEPlayers 
) 
SELECT Id, Name, @total = Total 
FROM Final_Results c 
WHERE RowNumber>@pageSize*(@pageNumber-1) AND RowNumber<@pageSize*@pageNumber;