rails joins where
跳到 joins - Active Record lets you use the names of the associations defined on the model as a shortcut for specifying JOIN clauses for those associations ... , so that is what Rails joins on. This is just how Rails works when you pass a Symbol to . joins , and is why the error refers to the association when you pass a Symbol not matching any existing assocation for your model. Also described in the Rails Guide,,User.joins("LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id") # SELECT "users".* FROM "users" LEFT ... , You need to rewrite the query since ads_attributes is not a table, Try this ads_params = @ads_params.require(:ads).permit(:id).to_h ..., Try joins with where on the joined table: ... class Store < ActiveRecord::Base belongs_to :company delegate :category, :to => :company end., 在Rails專案中常常需要撈關聯的資料，或者是用關聯資料的欄位當成判斷條件來撈需要的資料。ActiveRecord的joins方法將SQL的INNER JOIN包裝 ..., Rails當中要連結model之間的關係非常簡單，不過也因為由於建立關係是這樣的簡便，造成許多指令會在讀取資料庫時有記憶體的浪費。例如我們 ..., This should work: User.joins(:pets).where("pets.name != 'fluffy'"). Also you might want to read the following part (on joins ) on the official RoR ...,跳到 joins 和includes 查詢 - 透過joins抓出來的event物件是沒有包括其關連物件的，因為Rails預設只有 select event.* 而沒有 select categories.* ，因此joins ... , You can define in your user model has_many :user_tags has_many :tags, through: :user_tags. and then just use
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 rails joins where 相關參考資料
Active Record Query Interface — Ruby on Rails Guides
跳到 joins - Active Record lets you use the names of the associations defined on the model as a shortcut for specifying JOIN clauses for those associations ... https://guides.rubyonrails.org Deconstructing Rails .joins & .where methods - Stack Overflow
so that is what Rails joins on. This is just how Rails works when you pass a Symbol to . joins , and is why the error refers to the association when you pass a Symbol not matching any existing assoca... https://stackoverflow.com joins (ActiveRecord::QueryMethods) - APIdock
User.joins("LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id") # SELECT "users".* FROM "users" LEFT ... https://apidock.com Rails .joins() between tables and .where() condition - Stack Overflow
You need to rewrite the query since ads_attributes is not a table, Try this ads_params = @ads_params.require(:ads).permit(:id).to_h ... https://stackoverflow.com Rails where clause over two tables - Stack Overflow
Try joins with where on the joined table: ... class Store < ActiveRecord::Base belongs_to :company delegate :category, :to => :company end. https://stackoverflow.com Rails: joins的使用- 李威辰- Medium
在Rails專案中常常需要撈關聯的資料，或者是用關聯資料的欄位當成判斷條件來撈需要的資料。ActiveRecord的joins方法將SQL的INNER JOIN包裝 ... https://medium.com Rails使用include 和join 避免N+1 query | Motion Express ...
Rails當中要連結model之間的關係非常簡單，不過也因為由於建立關係是這樣的簡便，造成許多指令會在讀取資料庫時有記憶體的浪費。例如我們 ... https://motion-express.com Ruby on Rails ActiveRecord query using a join - Stack Overflow
This should work: User.joins(:pets).where("pets.name != 'fluffy'"). Also you might want to read the following part (on joins ) on the official RoR ... https://stackoverflow.com Ruby on Rails 實戰聖經| ActiveRecord - 資料表關聯
跳到 joins 和includes 查詢 - 透過joins抓出來的event物件是沒有包括其關連物件的，因為Rails預設只有 select event.* 而沒有 select categories.* ，因此joins ... https://ihower.tw Using a where clause with join clause in Rails activerecord ...
You can define in your user model has_many :user_tags has_many :tags, through: :user_tags. and then just use https://stackoverflow.com |