SQL 查询和数据库设计

Question

我正在为移动应用程序开发一个后端，使用 Laravel Lumen 和 MYSQL 作为按需交付服务的数据库，该应用程序的简单想法是用户创建一个取货请求（我有一个订单或多个订单，每个订单有自己的下车地点），司机应在地图上跟踪上车地点和下车地点。

最终我得到了包含取货省、取货地点、取货时间等的取货表和包含作为外键的取货 ID、下车省、下车地点和其他订单详细信息的订单表。

现在说得更清楚：

1 pickup may have 1 order within, 
1 pickup may have 5 orders within

我需要的是在 1 个查询中同时获取与司机特定省份相关的接送地点和下车地点，这可能吗？如果不是，解决这个问题的最佳数据库设计是什么。

任何帮助将不胜感激

Answer 1

假设每个订单都有一个且只有一个取货地点，我会将您的架构更改为有一个 locations 表。

locations
  id
  name
  address
  province
  ...etc...

orders
  id
  pickup_id references locations
  pickup_at
  dropoff_id references locations
  dropoff_at
  ...more info about the order...

您可能需要单独的接送表和下车表，每个表都引用位置，但重要的是要将位置标准化为单个表并引用它。

现在我们可以将订单与其位置关联起来。订单及其取货地点的基本查询是...

select ...
from orders o
join locations lp on lp.id = o.pickup_id
join locations ld on ld.id = o.dropoff_id
where ...
group by o.id;

我们可以使用它来查找在某个省份有取货或送货的订单。

select
  o.id,
  lp.name as pickup,
  lp.province as pickup_province,
  ld.name as dropoff,
  ld.province as dropoff_province
from orders o
join locations lp on lp.id = o.pickup_id
join locations ld on ld.id = o.dropoff_id
where ? in (lp.province, ld.province)
group by o.id;

某个位置的订单。

select o.id, lp.name as pickup, ld.name as dropoff
from orders o
join locations lp on lp.id = o.pickup_id
join locations ld on ld.id = o.dropoff_id
where ? in (lp.name, ld.name)
group by o.id;

订单完全在一个省内。

select o.id, ld.province as province
from orders o
join locations lp on o.pickup_id = lp.id
join locations ld on o.dropoff_id = ld.id
where lp.province = ld.province
group by o.id

还有更多。

dbfiddle