通過聯盟查詢創建運行餘額總計

Question

我們有一個跟蹤客戶獎勵積分的web應用程序。我們正在使用MySQL數據庫。 我本來是從一個單一的表餘額（RunningTotal）拖着走的數據並顯示點的數量在每次交易查詢的代碼如下：

SELECT DateSubmitted 
, PointTotal as Points 
, (SELECT SUM(PointTotal) 
     FROM ptrans_detail x 
      WHERE x.CustID = a.CustID 
      AND (x.DateSubmitted < a.DateSubmitted OR x.DateSubmitted = a.DateSubmitted)) AS RunningTotal 
, comment 
    FROM ptrans_detail a 
    WHERE CustID='10009' 
    Order by TransID Desc 

這工作得很好，直到它被發現有人未在ptrans_detail表中存在的一些條目，這個問題被張貼在這裏： Query Data from 2 MySQL tables with some duplicate records

至於建議，我用聯盟2個查詢從2個表結合起來，讓所有的記錄，查詢是：

SELECT CustID 
     , DateSubmitted 
     , Type 
     , Points 
      FROM `trans_summary` 
      WHERE CustID = '10009' 
UNION 

SELECT CustID 
, DateSubmitted 
, Type 
, PointTotal 
    FROM `ptrans_detail` 
     WHERE CustID = '10009' 
      and DateSubmitted NOT IN 
      (SELECT DateSubmitted FROM 
      `trans_summary` 
       WHERE CustID = '10009') 

這很好，但現在我想在第一個查詢中添加RunningTotal。這可能嗎？

Answer 1

你想這樣的：

SELECT CustID, DateSubmitted, Type, SUM(Points) FROM (SELECT CustID 
      , DateSubmitted 
      , Type 
      , Points 
       FROM `trans_summary` 
       WHERE CustID = '10009' 
    UNION 

    SELECT CustID 
    , DateSubmitted 
    , Type 
    , PointTotal as Points 
     FROM `ptrans_detail` 
      WHERE CustID = '10009' 
       and DateSubmitted NOT IN 
       (SELECT DateSubmitted FROM 
       `trans_summary` 
        WHERE CustID = '10009')) AS tr_summery 

Answer 2

我會建議你使用union all，除非你真的需要union。

獲得MySQL中的運行總和，最簡單的方法是使用變量：

SELECT t.*, 
     (@sump := if(@c = CustId, @sump + Points, 
        if(@c := CustId, Points, Points) 
        ) 
     ) as runningTotal 
FROM (SELECT CustID, DateSubmitted, Type, Points 
     FROM trans_summary 
     WHERE CustID = '10009' 
     UNION ALL -- Maybe it should be `UNION` 
     SELECT CustID, DateSubmitted, Type, PointTotal 
     FROM ptrans_detail 
     WHERE CustID = '10009' AND 
      DateSubmitted NOT IN (SELECT ts.DateSubmitted FROM trans_summary ts WHERE ts.CustID = '10009') 
    ) t CROSS JOIN 
    (SELECT @c := -1, @sump := 0) params 
ORDER BY CustId, DateSubmitted;