Question

我没有使用sqlite3 gem
我正在使用mysql2 gem

我从MySQL数据库中检索数据，因为它符合某个event type和severity的条件。但是，它只返回一行而不是结果数组。这让我很困惑。不应该.map返回一个数组？

   result = connect.query("SELECT * FROM data WHERE event_type = 'ALARM_OPENED' AND severity = '2'") 
    equipments = result.map do |record| 
        [
            record['sourcetime'].strftime('%H:%M:%S'), 
            record['equipment_id'], 
            record['description']
        ]
    end
    p equipments

Answer 1

我误解了你的问题...我认为你在寻找的是here。

<强>更新

你可以改用它们，如下所示：

#!/usr/bin/env ruby
require 'mysql2'

connect= Mysql2::Client.new(:host => '', :username => '', :password => '', :database => '')

equipments = []
result = connect.query("SELECT * FROM data WHERE event_type = 'ALARM_OPENED' AND severity = '2'", :symbolize_keys => true).each do |row|
    equipments << [ 
                    row[:sourcetime].strftime('%H:%M:%S'), 
                    row[:equipment_id], 
                    row[:description] 
                  ]
end

puts "#equipments {equipments}"

编辑：

我忘了在查询结尾添加.each。所以它返回了初始化的空数组。

Answer 2

您必须更改您的sql语句：

result = connect.query("SELECT * FROM data WHERE event_type = 'ALARM_OPENED' AND severity = '2'", :as => :array)

从MySQL检索数组

2 个答案: