Question

我在我的项目中使用续集，我遇到了从db获取非唯一记录ID的问题。我有下表：

table = Sequel::Model.db[:csv_temp]

并且该表中的记录如下所示：

table.all

[{:id=>1,
  :school_identifier=>"school_id_1",
  :school_name=>"school_name_1",
 },
 {:id=>2,
  :school_identifier=>"school_id_1",
  :school_name=>"school_name_2",
 }]

如何获取school_identifier不唯一的记录ID？

Answer 1

这是一种方法，可能还有其他方法：

DB[:csv_temp].
  where(:school_identifier=>DB[:csv_temp].
    select_group(:school_identifier).
    having{count{}.* > 2}).
  select_map(:id)

用续集获取非唯一记录

1 个答案: