Mysql2 ::結果到對象

Question

如何將Mysql2 :: Result結果轉換爲某個對象？ 我使用：

@users = ActiveRecord::Base.connection.execute("SELECT sum(summ) as prize, u.* FROM `tournaments` t, `users` u WHERE u.id = t.user_id GROUP BY t.user_id ORDER BY prize desc LIMIT 10") 

我需要這個結果映射到某個物體，或smthg這樣。 謝謝。

Answer 1

我的理解是，你可以在任何模型上執行這樣的SQL查詢，它會返回數據作爲該模型的實例。請閱讀find_by_sql。這是來自文檔的示例。請注意，是返回一個Post對象：

Post.find_by_sql "SELECT p.title, c.author FROM posts p, comments c WHERE p.id = c.post_id" 
> [#<Post:0x36bff9c @attributes={"title"=>"Ruby Meetup", "first_name"=>"Quentin"}>, ...] 

Rails 3的查詢語法應該給你所有你需要拿到雖然此信息。我會盡可能避免使用原始SQL，您可以非常快速地將它綁定到特定的數據庫。看看here獲得一些靈感。

傳遞PARAMS到的find_by_sql可以這樣做：

irb(main):015:0> y Location.find_by_sql(["select address, name from locations where name = :name and address = :address", {:address => "Arts Court 2 Daly Ave, Ottawa, ON", :name => "Studio B"}]) 
--- 
- !ruby/object:Location 
    attributes: 
    name: Studio B 
    address: Arts Court 2 Daly Ave, Ottawa, ON 
    attributes_cache: {} 

changed_attributes: {} 

destroyed: false 
marked_for_destruction: false 
new_record: false 
previously_changed: {}