ruby-on-rails - 如何使用 rails 和 postgres 改进查询

Question

我有三个模型posts有一个 post_rating，post_waiting_time

post.rb

name_column      type           example 
id               integer           20
name             string           'welcome'
user_id          integer           1

post_rating.rb

name_column      type           example 
id               integer           10
rating_label     enum           poor,average,great
post_id          integer           20

post_waiting_time.rb

name_column      type           example 
id               integer           10
waiting_label     enum           0-3,4-6,7-10
post_id          integer           20

我尝试在查询使用中使用 rating_label、waiting_label eager_load，joins 但不能在查询中写入多标签

posts_lists = user.posts.eager_load(:post_rating, :post_waiting_time).where("post_waiting_times.waiting_label = ? ", '0-3')

此查询适用于一个值，但我需要多个查询使用 waiting_label 例如0-3, 4-7我尝试使用IN() but i have error

Post.eager_load(:post_rating, :post_waiting_time).where('post_waiting_times.waiting_label IN( ? )', 'more_30,0-
3')

最后一次查询的错误信息

ActiveRecord::StatementInvalid (PG::InvalidTextRepresentation: ERROR:  invalid input value for enum tag_label: "more_30,0-3")
LINE 1: ...ERE (post_waiting_times.waiting_label IN( 'more_30,0...

我通过编写过滤器查询来解决此问题rating_label，waiting_label

posts_lists = user.posts
posts_lists.each do |record|
        flag_filter = false
        unless waiting_filter.empty?
          flag_filter = if waiting_filter.include?(record.post_waiting_time.waiting_label)
                          true
                        else
                          false
                        end
        end

        unless rating_filter.empty?
          flag_filter = if rating_filter.include?(record.post_rating.rating_label)
                          true
                        else
                          false
                        end
        end
    if flag 
       puts record
    end 

但这不是效率的方式

我用Rails 6，PostgreSQL

标签： ruby-on-railspostgresql

Answer 1

你做错了，你可以直接在rails中传递一个数组进行比较。这是更新的查询

Post.eager_load(:post_rating, :post_waiting_time).where(post_waiting_times: {waiting_label: ['more_30','0-3']})

希望这能解决问题。