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AR声明:在下面的MySQL查询排除ID列从ActiveRecord的结果
Phone.select(:number).distinct.where(in_black_list: true)
结果:
SELECT DISTINCT number FROM phones WHERE phones.in_black_list = 1
结果中包含空的标识:
#<ActiveRecord::Relation [
#<Phone id: nil, number: "1234567">,
#<Phone id: nil, number: "78567459">,
#<Phone id: nil, number: "78567457">,
#<Phone id: nil, number: "998567946794567">,
]>
如何消除这些ID ?