如何在bookshelfJS中编写嵌套查询

Question

以下是样本Db结构

我希望结果在bookshelfjs中，以便

1）广告系列表

中的所有列

2）一列将具有实例数量的列属于广告系列

3）一列将具有实例数量的列属于一个广告系列，并且status_id = 3

我知道原始查询：

form_for(@user, url: admin_resource_path(@user)

我使用

尝试了相同的查询

 select campaign.*, 
     (select count(*) from instance where instance.campaign_id=campaign.id) as totalInstances,
     (select count(*) from instance where instance.campaign_id=campaign.id and instance.status.id=3) as duplicateInstances 
 from campaign

但没有运气。我怎样才能做到这一点？

Answer 1

knex('campaign').select([
  'campaign.*', 
  (builder) => builder
    .count('*')
    .from('instance')
    .where('instance.campaign_id', knex.raw('??', ['campaign.id']))
    .as('totalInstances'), 
  (builder) => builder
    .count('*')
    .from('instance')
    .where('instance.campaign_id', knex.raw('??', ['campaign.id']))
    .where('instance.status.id', 3)
    .as('duplicateInstances')
]).toSQL()

select 
  "campaign".*, 
  (select count(*) from "instance" where "instance"."campaign_id" = "campaign"."id") as "totalInstances", 
  (select count(*) from "instance" where "instance"."campaign_id" = "campaign"."id" and "instance"."status"."id" = ?) as "duplicateInstances" 
  from "campaign"