錯誤結合2個SQL查詢一起

Question

請看看下面的代碼

SELECT ongoing_portfolio.*, 
Portfolio.Activation 
FROM Ongoing_Portfolio 
INNER JOIN Portfolio ON Ongoing_Portfolio.idPortfolio = Portfolio.idPortfolio 
WHERE ongoing_portfolio.`idPortfolio`= 2 ORDER BY `Updated_Date` DESC LIMIT 4 

---

SELECT SUM(`Transaction_Amount`) AS `Total` 
FROM `transactions` 
WHERE `idPortfolio`= 2 AND `Transaction_TimeStamp` <= "2016-12-17" 

其實我試圖在這裏做的就是這個。

1. 獲取所有投資組合的財務詳情（第一個查詢）。
2. 獲取第一個查詢引用的特定投資組合的提及日期的總交易爲Updated_Date。 （第二個查詢）

現在，我真的需要在一個查詢中這樣做，所以我在下面嘗試。

SELECT ongoing_portfolio.*, 
Portfolio.Activation, 
SUM(Transactions.`Transaction_Amount`) AS `Total` WHERE `Transaction_TimeStamp` <= ongoing_portfolio.`Updated_Date` 
FROM Ongoing_Portfolio 
INNER JOIN Portfolio ON Ongoing_Portfolio.idPortfolio = Portfolio.idPortfolio 
INNER JOIN Transactions ON Transactions.`idPortfolio` = Ongoing_Portfolio.idPortfolio 
WHERE ongoing_portfolio.`idPortfolio`= 2 ORDER BY `Updated_Date` DESC LIMIT 4 

然而，因爲它說

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE `Transaction_TimeStamp` <= ongoing_portfolio.`Updated_Date` 
FROM Ongoing_' at line 3 

我怎樣才能使這個查詢成功後，該生成錯誤？

Answer 1

在檢索列中不能使用where條件。 您可以使用其他條件或總數。

SELECT ongoing_portfolio.*, 
     Portfolio.Activation, 
     SUM(case when Transaction_TimeStamp` <= ongoing_portfolio.`Updated_Date` 
      then Transactions.`Transaction_Amount` end) AS `Total` FROM Ongoing_Portfolio 
     INNER JOIN Portfolio ON Ongoing_Portfolio.idPortfolio = Portfolio.idPortfolio 
     INNER JOIN Transactions ON Transactions.`idPortfolio` = Ongoing_Portfolio.idPortfolio 
     WHERE ongoing_portfolio.`idPortfolio`= 2 group by 'Updated_Date' 
ORDER BY `Updated_Date` DESC LIMIT 4