first_or_initialize不适用于相对模型，每次都会创建新记录

Question

ccs.each do |cd|
  relative_model = main_model.relative_model.where(start_date: XYZ, end_date: XYZ).first_or_initialize
  relative_model.capacity = cd['capacity'].to_f
  relative_model.save!
end

根据上面的代码，first_or_initialize不能处理相关模型，每次都会创建新的记录。

下面是两个inr在后台运行的查询：

SELECT `capacity_commitments`.* FROM `capacity_commitments`  WHERE `capacity_commitments`.`participants_subscription_id` = 1 AND `capacity_commitments`.`start_date` = '2016-11-16' AND `capacity_commitments`.`end_date` = '2016-11-21'

SELECT `capacity_commitments`.* FROM `capacity_commitments`  WHERE `capacity_commitments`.`participants_subscription_id` = 1 AND `capacity_commitments`.`start_date` = '2016-11-16' AND `capacity_commitments`.`end_date` = '2016-11-21'

需要初始帮助或指出上述代码中的错误之处？

Answer 1

尝试使用find_or_initialize_by方法

relative_model =  main_model.relative_model.find_or_initialize_by(start_date: XYZ, end_date: XYZ)