Question

每个用户都有很多SaleItems和多个NeededItems。我想查询User 1的SaleItem名称，看看它们中是否有任何一个名称与User 2的NeededItems相似（＆＃34; name＆＃34;是唯一的属性）

@needed_item_of_user2 = NeededItem.where("user_id = ?", 2).first  
# "Pikachu Pokemon card"
@sale_items_of_user1 = SaleItem.where("user_id = ?", 1) 
# "Baseball cards", "Water Heater", "Pikachu doll", "Squirtle Pokemon card"
@matching_sale_items = @sale_items_of_user1.some_method_querying_the_names.@needed_item_of_user2.name 
# It should output either "Squirtle Pokemon card" (high accuracy) or 
# all except "Water Heater" (low accuracy)

我应该使用什么方法来获得@matching_sale_items?

的准确匹配

我试过了：

@matching_sale_items = @sale_items_of_user1.select do |sale| 
  sale["name"] == @needed_item_of_user2.name
end

基于How do I search within an array of hashes by hash values in ruby?

和

@matching_sale_items = @sale_items_of_user1.map do |a|
  a.name.downcase
end.grep(/#{@needed_item_of_user2.name.downcase[0,4]}/)  
# outputs strings

将来，我想使用该方法在SaleItems表中查询与NeedItems表的匹配。

Answer 1

您可以尝试这样做：

user1 = User.find 1
user2 = User.find 2
needed_items_names = user2.needed_items.pluck(:name)
matched_items = user1.sale_items.where(name: needed_items_names)

要阅读的文档：

Rails：根据另一个数组中的记录（字符串）查询数组

1 个答案: