Mysql 获取多个表的总和

表示例：

branch
----------------------------------
branchID | branchName | brMgrName|
----------------------------------
|      1  | a         |Tom       |
|      2  | b         |Jeff      |
|      3  | c         |Lin       |
----------------------------------

order
----------------------
orderID   | branchID |
----------------------
|   1     |     2   | 
|   2     |     2   | 
|   3     |     3   | 
----------------------


payment
--------------------------------
paymentID | orderID | p-amount |
--------------------------------
|   1     |     1   |   50.00  |
|   2     |     2   |  126.00  |
|   3     |     3   |   50.00  |
--------------------------------

我想要的输出是

-------------------------------------------
| branchName | brMgrName | Total Amount   |
-------------------------------------------
|      a     |  Tom      |     0.00       |
|      b     |  Jeff     |   252.00       |
|      c     |  Lin      |    50.00       |
-------------------------------------------

我试图确定如何在3个不同的表中汇总每个分支机构的金额

在输出中：
-branchName“a”没有订单表中的任何值，
-branchName“b”由paymentID 1和2相加，与
-分支名称“c”

通过加入分行和付款表，我已成功返回分行名称和总金额：

SELECT `order`.branchID, sum(`p-amount`)
FROM `order`
JOIN payment
ON `order`.orderID = payment.orderID
GROUP BY branchID

但是当我尝试下面的代码时，它返回了错误的值，并且只选择了1行

SELECT branchName, brMgrName, sum(`p-amount`)
FROM branch, payment
JOIN (SELECT `order`.branchID, sum(`p-amount`)
      FROM `order`
      JOIN payment
      ON `order`.orderID = payment.orderID
      GROUP BY branchID) b
ON b.branchID = branchID;

非常感谢您的帮助。

试试以下方法：

SELECT b.branchName, brMgrName, sum(p.`p-amount`)
  FROM branch b
        LEFT JOIN `order` o
                ON b.branchID = o.branchID 
        LEFT JOIN payment p
                ON o.orderID = p.orderID 
GROUP BY b.branchName, brMgrName
ORDER BY 3 -- third column on select list

试试这个

SELECT `branch`.`branchID`, `branch`.`branchName`, `branch`.`brMgrName`, SUM(`payment`.`p-amount`)
FROM `branch`
JOIN `order` ON `branch`.`branchID` = `order`.`branchID`
JOIN `payment` ON `order`.`orderID` = `payment`.`orderID`
GROUP BY `branch`.`branchID`

---

使用

在表/列标识符中使用“order”和/或“-”只是要求trouble@Strawberry谢谢你指出这一点。这不能正确地总结。您使用了错误的列进行分组。您几乎肯定会给第三列指定一个别名（例如，

total

），以便您可以在其他地方更容易地引用它。

SELECT b.branchName,b.brMgrName,
ISNULL( (SELECT sum(p.pamount) FROM dbo.payment p   
WHERE p.orderID IN (SELECT o.orderid FROM dbo.[order] o
WHERE o.branchID=b. branchID)),0) FROM dbo.branch b