Question

请查看以下代码

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"

其实我在这里要做的就是这个。

获取所有投资组合的财务详细信息（首次查询）。
获取第一个查询引用的特定投资组合的Updated_Date日期的总交易。（第二个问题）

现在，我真的需要在一个查询中执行此操作，所以我在下面尝试过。

 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，这会产生错误，因为它说

#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

如何成功完成此一项查询？

Answer 1

您无法在检索列中使用where条件。您可以使用if else或when condition for total。

    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

将2个SQL查询组合在一起时出错

1 个答案: