如何为此查询编写rails的活动记录

Question

有没有人可以帮我写这个查询的活动记录..

SELECT c.name,c.profile_pic,cq.title FROM `coaches` as c join course_queries as cq on
    c.id = cq.coach_id WHERE cq.coach_id=1

class CourseQuery < ActiveRecord::Base belongs_to :student belongs_to :coach end

class Coach < ActiveRecord::Base has_many :course_queries end

Answer 1

你可以试试这种方式

Coach.joins(:course_queries).select("coaches.name,coaches.profile_pic,course_queries.title").where(:course_queries => {:coach_id => 1})

您可以将外部联接的eger加载用作

@coaches = Coach.includes(:course_queries).where(:course_queries => {:coach_id => 1})

按

选择您的数据

 @coaches.each do |coach|
    puts coach.name
    puts coach.course_queries.first.title   
   end

您可以通过

获取所有课程查询

  @coaches.each do |coach|
    puts coach.name
    coach.course_queries.each do |course_query|
       puts course_query.title 
     end
   end