2个表列之间的SQL差异[关闭]答案

【问题标题】：SQL difference between 2 table columns [closed]2个表列之间的SQL差异[关闭]
【发布时间】：2021-02-13 06:48:49
【问题描述】：

场景：
一家工厂每天生产各种尺寸和规格 (swg) 的钢管，记录并存储在 pipe_production 表中（管道表的 pipe_id 外键）。该工厂还有定期向其销售管道的客户，根据要求创建发票并将其记录在发票表中。随后，与每个发票相关的管道存储在 pipe_invoices 表中。当销售团队的成员对发票进行授权时，invoices 表中的授权列从 false 切换为 true (0 => 1 in)，并表示这些管道将被出售并应从库存中移除。

我正在寻找一个查询来生成库存表，以便在现场准确评估管道。但是，我只想找出生产的管道和授权发票管道之间的区别。

应用程序正在 Laravel 框架上构建。

表格：管道

id | description | swg | min_weight | max_weight
1  | 2" X 2"     | 16  | 10         | 11
2  | 2" X 2"     | 18  | 8          | 19
3  | 1" X 2"     | 18  | 4          | 6

表：pipe_productions

id | pipe_id | quantity | production_date
1  | 1       | 1000     | 2020-10-1
2  | 2       | 2000     | 2020-10-1
3  | 3       | 5500     | 2020-10-1

表格：发票

id | client_id | authorised | loaded | invoice_date
1  | 1         | 0          | 0      | 2020-10-09
2  | 2         | 1          | 0      | 2020-10-09
3  | 2         | 1          | 1      | 2020-10-09

表：pipe_invoices

id | invoice_id | pipe_id | quantity 
1  | 1          | 3       | 2000
2  | 1          | 1       | 1000
3  | 2          | 2       | 1000

编辑：我的当前查询仅获取 pipe_production 和 pipe_invoices 之间的区别。它不考虑发票未经授权且不应删除的情况。

SELECT *, coalesce(a.quantity, 0)-coalesce(b.quantity, 0) as diff
FROM
(SELECT pipe_id, sum(quantity) as quantity
FROM pipe_productions
GROUP BY pipe_id) a
LEFT JOIN
(SELECT pipe_id, sum(quantity) as quantity
FROM pipe_invoices
GROUP BY pipe_id) b
on a.pipe_id = b.pipe_id
LEFT JOIN pipes
on a.pipe_id = pipes.id
WHERE coalesce(a.quantity, 0)-coalesce(b.quantity, 0) != 0
ORDER BY swg asc, pipe_description desc

【问题讨论】：

标签： mysql sql laravel join difference

【解决方案1】：

我假设您只需要对您的查询稍作调整并在您的 b 语句中加入 invoices：

SELECT *, coalesce(a.quantity, 0)-coalesce(b.quantity, 0) as diff
FROM
(
   SELECT pipe_id, sum(quantity) as quantity
   FROM pipe_productions
   GROUP BY pipe_id
) a
LEFT JOIN
(
   SELECT pipe_id, sum(quantity) as quantity
   FROM pipe_invoices  pi
   JOIN invoices i ON pi.invoice_id = i.id
   WHERE i.authorised = 1
   GROUP BY pipe_id
) b
   on a.pipe_id = b.pipe_id
LEFT JOIN pipes
   on a.pipe_id = pipes.id
WHERE coalesce(a.quantity, 0)-coalesce(b.quantity, 0) != 0
ORDER BY swg asc, pipe_description desc

【讨论】：