在查询输出

Question

字段太多我有一个查询，我只希望输出三个变量

Relationship.select('follower_id as source, followed_id as target, value').map(&:attributes) 

但是我得到的结果包括id变量如下，我不想。我如何摆脱它？

{"source"=>1, "target"=>3, "value"=>1, "id"=>nil}, 
{"source"=>1, "target"=>4, "value"=>1, "id"=>nil}, 
{"source"=>1, "target"=>5, "value"=>1, "id"=>nil}, 
{"source"=>2, "target"=>3, "value"=>1, "id"=>nil} 

Answer 1

select总是返回id属性，你可以在map摆脱它：

Relationship.select('follower_id as source, followed_id as target, value').map{|x| [x.source, x.target, x.value]}