mysql - 使用查询的别名与另一个表 MySQL 连接

Question

我有 3 个表。

support_works = 包含序列号
kickscooters = contian serial_number, kickscooter_id(作为主ID，命名ID)
租金 = 包含 kickscooter_id。

我正在尝试获取满足条件的 support_works 的 serial_number，然后将其与 kickscooter 的 serial_number 相匹配。然后获取它的 kickscooter_id 以获取所有与从中检索到的 kickscooter_id 匹配的租金。

目前:

select k.id
     from support_works sw
     join kickscooters k
       on k.serial_number = sw.serial_number
     where
       sw.work_type = 'deploy' and
       (sw.updated_at between '2019-11-01 02:00:00' and '2019-11-01 10:00:00') and 
       k.id in (select kcu.kickscooter_id
                from kickscooter_control_units kcu
                where kcu.particle_product_id in (9358, 9383)));

这非常适合从 kickscooter 表中获取 kickscooter_id。但我现在使用它作为子查询来获取所有租金表数据，其中 rents.kickscooter_id 在此子查询中:

select *
from rents r
where r.kickscooter_id
  in (select k.id
     from support_works sw
     join kickscooters k
       on k.serial_number = sw.serial_number
     where
       sw.work_type = 'deploy' and
       (sw.updated_at between '2019-11-01 02:00:00' and '2019-11-01 10:00:00') and 
       k.id in (select kcu.kickscooter_id
                from kickscooter_control_units kcu
                where kcu.particle_product_id in (9358, 9383)));

这花费的时间太长，我想使用多个连接来加快速度。我该怎么做？

我一直在使用 CTE，但我读到它在创建/删除临时表时会占用内存，因此尽量避免使用它。

Answer 1

您可以在您的子查询上加入kickscooter_control_units，使用exists关键字而不是IN。

select *
from rents r
where 
  exists 
  (select 1
     from support_works sw
     join kickscooters k on k.serial_number = sw.serial_number
     join kickscooter_control_units kcu on  kcu.kickscooter_id =  k.id and kcu.particle_product_id in (9358, 9383)   
     where
       sw.work_type = 'deploy' and
       (sw.updated_at between '2019-11-01 02:00:00' and '2019-11-01 10:00:00'))  

根据您的情况，您似乎正在过滤 ID。 exists 仅适用于您要检查某个子查询 是否包含值的情况。

 select *
    from rents r
    where 
      r.kickscooter_id in 
      (select k.id
         from support_works sw
         join kickscooters k on k.serial_number = sw.serial_number
         join kickscooter_control_units kcu on  kcu.kickscooter_id =  k.id and kcu.particle_product_id in (9358, 9383)   
         where
           sw.work_type = 'deploy' and
           (sw.updated_at between '2019-11-01 02:00:00' and '2019-11-01 10:00:00'))