MySQL 多个表中多行的总和

Question

我试图从 2 个不同的表中获取多行的总和，但结果以某种方式返回了多行。

我需要获取 quotation_item_amount（按 quotation_id 分组）和 invoice_item_amount（按 invoice_id 分组）的总和，如果我查询未付报价，我需要获取 WHERE SUM(invoice) < SUM(quotation)

所以这是我的示例表

table client_project_id
+-------------------+-----------+----------------------+
| client_project_id | client_id | client_project_title |
+-------------------+-----------+----------------------+
|         23        |     5     |        Project 1     |
|         17        |     9     |        Project 2     |
|         54        |     7     |        Project 3     |
+-------------------+-----------+----------------------+

table quotation
+--------------+-------------------+------------------+
| quotation_id | client_project_id | quotation_number |
+--------------+-------------------+------------------+
|       1      |          23       |   Q/01/2020/001  |
|       2      |          17       |   Q/01/2020/002  |
|       3      |          54       |   Q/01/2020/003  |
+--------------+-------------------+------------------+

table quotation_item
+-------------------+--------------+-----------------------+
| quotation_item_id | quotation_id | quotation_item_amount |
+-------------------+--------------+-----------------------+
|         1         |     1        |          500          |
|         2         |     1        |          700          |
|         3         |     1        |          600          |
|         4         |     2        |          200          |
|         5         |     2        |          150          |
|         6         |     3        |          900          |
+-------------------+--------------+-----------------------+

table invoice
+--------------+-------------------+------------------+
|  invoice_id  | client_project_id |  invoice_number  |
+--------------+-------------------+------------------+
|       1      |          23       |   I/01/2020/001  |
|       2      |          17       |   I/01/2020/002  |
|       3      |          54       |   I/01/2020/003  |
+--------------+-------------------+------------------+

table invoice_item
+-------------------+--------------+-----------------------+
|  invoice_item_id  |  invoice_id  |  invoice_item_amount  |
+-------------------+--------------+-----------------------+
|         1         |     1        |          500          |
|         2         |     1        |          700          |
|         3         |     1        |          600          |
|         4         |     2        |          200          |
|         5         |     2        |          150          |
|         6         |     3        |          900          |
+-------------------+--------------+-----------------------+

我需要得到的结果是：

1. quotation_item_amount 的 SUM 和 invoice_item_amount 的 SUM PER client_project_id
2. 查询 WHERE SUM(invoice) < SUM(quotation)

这是我最近的查询尝试

SELECT 
    SUM(quotation_item.quotation_item_amount) as quot_amt, 
    SUM(invoice_item.invoice_item_amount) as inv_amt,
    data_client_project.client_project_id,
    data_client.client_name

FROM data_client_project a
LEFT JOIN quotation b ON a.client_project_id = b.client_project_id
LEFT JOIN data_client d ON a.client_id = d.client_id
LEFT JOIN invoice i ON a.client_project_id = i.client_project_id
JOIN (
        SELECT quotation_id, 
            SUM(c.quotation_item_amount) as quot_amt
        FROM quotation_item c 
        GROUP BY c.quotation_id
      ) quotitem
        ON b.quotation_id = quotitem.quotation_id
        JOIN (
            SELECT invoice_id, 
                SUM(e.invoice_item_price) as inv_amt
            FROM invoice_item e
            GROUP BY e.invoice_id
        ) invitem
        ON i.invoice_id = invitem.invoice_id

但是，这会导致 quotation_item_amount 和 invoice_item_amount 的多个重复行。

已尝试使用 UNION / UNION ALL 和其他几个不起作用的查询。 谢谢你的所有建议。

Answer 1

看起来您正在尝试同时沿两个不同的维度进行聚合。 解决方案是沿每个维度进行预聚合：

SELECT *
FROM data_client_project cp LEFT JOIN
     (SELECT q.client_project_id,
             SUM(qi.quotation_item_amount * qi.quotation_item_qty) as quot_amt
      FROM quotation q JOIN
           quotation_item qi
           ON qi.quotation_id = q.quotation_id
      GROUP BY q.client_project_id
     ) q
     USING (client_project_id) LEFT JOIN
     (SELECT i.client_project_id,
             SUM(invoice_item_price) as inv_amt
      FROM invoice i JOIN
           invoice_item ii
           ON i.invoice_id = ii.invoice_id
      GROUP BY i.client_project_id
     ) i
     USING (client_project_id);

关于您的风格的两个注意事项。

首先，您使用任意字母作为表别名。 如果您添加新表、删除表或重新排列名称，这会使查询很难遵循并且变得很尴尬。 对表格使用缩写。 更容易遵循。

其次，我真的不推荐SELECT *用于此类查询。 但是，您可以通过将ON替换为USING来避免重复的列。

Answer 2

我可能遗漏了一些东西，但您的表描述不包括data_client或data_client_project的示例根据您的示例，我希望您的行扩展来自前 3 个连接。

确保下面首先为您提供所需的数据列表，然后尝试加入计算：

SELECT *
    FROM data_client_project a
    LEFT JOIN quotation b ON a.client_project_id = b.client_project_id
    LEFT JOIN data_client d ON a.client_id = d.client_id
    LEFT JOIN invoice i ON a.client_project_id = i.client_project_id;
#you may want to append the above with a limit 100 for testing.

Answer 3

如果您在主查询中有重复的行，则为 obatin 添加不同的行，并且添加用于通过 quotitem.quot_amt < invitem.inv_amt 过滤结果的条件

    SELECT distinct a.*, b.*, d.*, i.*  
    FROM data_client_project a
    LEFT JOIN quotation b ON a.client_project_id = b.client_project_id
    LEFT JOIN data_client d ON a.client_id = d.client_id
    LEFT JOIN invoice i ON a.client_project_id = i.client_project_id
    JOIN (
            SELECT quotation_id, 
                SUM(c.quotation_item_amount * c.quotation_item_qty) as quot_amt
            FROM quotation_item c 
            GROUP BY c.quotation_id
          ) quotitem  ON b.quotation_id = quotitem.quotation_id
    JOIN (
            SELECT invoice_id, 
                SUM(e.invoice_item_price) as inv_amt
            FROM invoice_item e
            GROUP BY e.invoice_id
            ) invitem  ON i.invoice_id = invitem.invoice_id
    WHERE quotitem.quot_amt < invitem.inv_amt