Rails ActiveRelation来哈希

Question

我需要哈希化ActiveRelation!例如,我有这样的AR

arel = MyClass.page(options[:page]).per(options[:per]) 

这是一种简单的方法来创建散列,其中MyTable的主键作为散列中的键

EX1:

[#<Object id: 44, name: "name44" >, #<Object id: 2, name: "name2" >, #<Object id: 110, name: "name110">]
=>
{44=>"name44", 2=>"name2",110=>"name110"}

EX2:

[#<Object id: 44, name: "name44" >, #<Object id: 2, name: "name2" >, #<Object id: 110, name: "name110">]
=>
{44=>{:id=>44, :name=>"name44", 2=>{:id=>2,:name=>"name2"},110=>{:id=>110,:name=>"name110"}}

Answer 1

试试index_by:

MyClass.limit(20).all.index_by(&:id)

http://api.rubyonrails.org/classes/Enumerable.html#method-i-index_by