Mysql 组合三个（复杂）查询_Mysql

Mysql 组合三个（复杂）查询

mysql

Mysql 组合三个（复杂）查询,mysql,Mysql,我有一个查询，我用它来汇总库存总额，并显示每个库存项目的最后更新日期。我有两种不同的库存类型0和1（传入和传出）。我想能够在页面底部写上“上次收到的库存在：&”上次装运在：“ 以下是我的主要查询内容，用于对库存进行分组和汇总： $query = "Select * FROM (SELECT id, type, color, product, SUM(Quantity) AS TotalQuantity, MAX(Date) A

我有一个查询，我用它来汇总库存总额，并显示每个库存项目的最后更新日期。我有两种不同的库存类型0和1（传入和传出）。我想能够在页面底部写上“上次收到的库存在：&”上次装运在：“

以下是我的主要查询内容，用于对库存进行分组和汇总：

 $query = "Select * 
          FROM (SELECT id, type, color, product, 
                      SUM(Quantity) AS TotalQuantity, MAX(Date) AS LatestDate 
                FROM inventory 
                GROUP BY id, color, type) AS alias 
          WHERE TotalQuantity > 0";

现在，我还希望能够运行这两个查询，以获取“stock”0和1（传入、传出）的上次更新时间

结合这三个查询有什么帮助吗？我试着结合，但运气不太好。

试试这样：

SELECT  alias.*,
    zeroStock.zeroDate,
    nonzeroStock.nonzeroDate
FROM
    (
        SELECT  id, 
            type, 
            color, 
            product, 
            SUM(Quantity) AS TotalQuantity, 
            MAX(Date) AS LatestDate 
        FROM    inventory 
        GROUP BY id, color, type
    ) alias INNER JOIN
    (
        SELECT id, MAX(Date) zeroDate
        FROM inventory 
        WHERE stock = 0
        GROUP BY id
    ) zeroStock on alias.id = zeroStock.id
    INNER JOIN
    (
        SELECT id, MAX(Date) nonzeroDate
        FROM inventory 
        WHERE stock = 1
        GROUP BY id
    ) nonzeroStock on alias.id = nonzeroStock.id
WHERE alias.TotalQuantity > 0

试着这样做：

SELECT  alias.*,
    zeroStock.zeroDate,
    nonzeroStock.nonzeroDate
FROM
    (
        SELECT  id, 
            type, 
            color, 
            product, 
            SUM(Quantity) AS TotalQuantity, 
            MAX(Date) AS LatestDate 
        FROM    inventory 
        GROUP BY id, color, type
    ) alias INNER JOIN
    (
        SELECT id, MAX(Date) zeroDate
        FROM inventory 
        WHERE stock = 0
        GROUP BY id
    ) zeroStock on alias.id = zeroStock.id
    INNER JOIN
    (
        SELECT id, MAX(Date) nonzeroDate
        FROM inventory 
        WHERE stock = 1
        GROUP BY id
    ) nonzeroStock on alias.id = nonzeroStock.id
WHERE alias.TotalQuantity > 0

您可以使用

交叉联接

将日期添加到常规select语句的每一行

SELECT  *
FROM    (
          SELECT  *
          FROM    (
                    SELECT id, type, color, product, SUM(Quantity) AS TotalQuantity, MAX(Date) AS LatestDate 
                    FROM inventory 
                    GROUP BY 
                          id, color, type
                  ) AS alias 
          WHERE TotalQuantity > 0
        ) AS q
        CROSS JOIN (SELECT MAX(Date) AS MaxIncoming FROM Inventory WHERE stock = 0) AS r
        CROSS JOIN (SELECT MAX(Date) AS MaxOutgoing FROM Inventory WHERE stock = 1) AS s

交叉连接也称为笛卡尔积连接。交叉连接 SQL返回一个结果表，其中第一个表中的每一行与第二个表中的每一行合并

编辑

对于记录，您可以使用

HAVING

子句而不是TotalQuantity上的

WHERE

子句来简化语句

SELECT  *
FROM    (
          SELECT  id, type, color, product, SUM(Quantity) AS TotalQuantity, MAX(Date) AS LatestDate 
          FROM    inventory 
          GROUP BY 
                  id, color, type
          HAVING
                  SUM(Quantity) > 0        
        ) AS q
        CROSS JOIN (SELECT MAX(Date) AS MaxIncoming FROM Inventory WHERE stock = 0) AS r
        CROSS JOIN (SELECT MAX(Date) AS MaxOutgoing FROM Inventory WHERE stock = 1) AS s