Question

我必须使用Ruby程序以下面指定的方式显示数据。有人可以帮助我，我该怎么做。必须在SQlcode或Ruby代码中进行更改。代码如下：

require 'sqlite3'
#db=SQLite3::Database.open ('adaptive.db')
class Database
    @@db=SQLite3::Database.open 'adaptive.db'
    def registered_users
        @@db.execute(
        "Select strftime('%Y-%m',created_at) AS Month, count(uuid) as    RegistredPeopleNo
        from users
        group by strftime('%Y-%m',created_at)
        order by Month;") do |row|
          p row
        end
      end
      def registered_devices
         @@db.execute(
         "Select strftime('%Y-%m',created_at) AS RegisteredMonth,
          count(serial_number) AS RegisteredDevicesNo
          from devices
          group by strftime('%Y-%m',created_at)
          order by RegisteredMonth;") do |row|
              p row
          end
       end
       def unregistered_users
         @@db.execute(
         "Select strftime('%Y-%m',updated_at) AS Unregister, count(id) AS Id
          from users
          where id not in(Select user_id from devices)
          group by strftime('%Y-%m',updated_at)
          order by Unregister;") do |row|
          p row
          end
       end
       def unregistered_devices
         @@db.execute(
         "Select strftime('%Y-%m',updated_at) AS Unregister,count(id) AS Id
          from devices
          where channel_id is null
          group by strftime('%Y-%m',updated_at);") do |row|
          p row
       end
     end
     def device_per_user
       @@db.execute(
       "select register AS NoOFMachines,count(id) as NoOFPeople
        from(
        Select users.id AS id,count(devices.id) AS register
        from users,devices
        where users.id=devices.user_id
        group by devices.user_id)
        group by register;") do |row|
          p row
        end
     end
  end

运行命令：

>irb
>require './database'
>db=Database.new
>db.registered_users#
The output is following:
["2015-08",23]
["2015-09",102]
["2015-10",59]
["2015-11",25]

但是，我希望它显示如下：

[["2015-08",23],["2015-09",102],["2015-10",59],["2015-11",25]]

有人可以帮我解决这个问题......提前致谢

Answer 1

将值存储在Array中。试试这个：

def registered_users
    arr = []
    @@db.execute(
    "Select strftime('%Y-%m',created_at) AS Month, count(uuid) as RegistredPeopleNo
    from users
    group by strftime('%Y-%m',created_at)
    order by Month;") do |row|
    arr << row
    end
    p arr
end

更新：您不需要each循环。可能在代码下面会给你你想要的结果。

@@db.execute(
  "Select strftime('%Y-%m',created_at) AS Month, count(uuid) as RegistredPeopleNo
  from users
  group by strftime('%Y-%m',created_at)
  order by Month;")`

使用Ruby程序水平显示从数据库中提取的数据

1 个答案: