Sequel根据条件加一个'scope'

Question

代码如下：

class Foo < Sequel::Model
  self.dataset_module do
    def property_active
      where('properties @> \'{"active": true}\'')
    end
  end
end

class Bar
  def foo_ids
    Foo.select(:other_model_id).distinct.all
  end

  def condition?
    ...
  end
end

我想修改 foo_ids 方法以根据 condition? 方法添加范围 property_active。到目前为止，我想出了这个：

Foo.select(:other_model_id).where{ Foo.property_active if condition? }.distinct

它 returns:

# when condition? is true
=> "SELECT DISTINCT \"other_model_id\" FROM \"foos\" WHERE (SELECT * FROM \"foos\" WHERE (properties @> '{\"active\": true}'))"

# when condition? is false
=> "SELECT DISTINCT \"other_model_id\" FROM \"foos\""

代码很好，但我不喜欢在 WHERE 之后添加 SELECT 的想法，有没有办法 return 对 true案例？类似于：

"SELECT DISTINCT \"other_model_id\" FROM \"foos\" WHERE (properties @> '{\"active\": true}')"

Answer 1

我不太熟悉 Sequel 处理链接和作用域的方式，但这就是我将如何使用 ActiveRecord 处理它的方式。这个有用吗？

class Bar
  def foo_ids
    scope = Foo.select(:other_model_id)
    scope = scope.property_active if condition?
    scope.distinct.all
  end
end

Sequel根据条件加一个'scope'

Sequel add a 'scope' according to a conditional

ruby

database

sequel