Rails 3 在没有模型的情况下执行自定义 sql 查询 [英] Rails 3 execute custom sql query without a model

问题描述

我需要编写一个独立的 ruby​​ 脚本来处理数据库.我在 rails 3 中使用了下面给出的代码

I need to write a standalone ruby script that is supposed to deal with database. I used code given below in rails 3

@connection = ActiveRecord::Base.establish_connection(
:adapter => "mysql2",
:host => "localhost",
:database => "siteconfig_development",
:username => "root",
:password => "root123"
)

results = @connection.execute("select * from users")
results.each do |row|
puts row[0]
end

但出现错误:-

`<main>': undefined method `execute' for #<ActiveRecord::ConnectionAdapters::ConnectionPool:0x00000002867548> (NoMethodError)

我在这里缺少什么?

解决方案

从 denis-bu 获得解决方案后，我按照以下方式使用它并且也有效.

After getting solution from denis-bu i used it following way and that worked too.

@connection = ActiveRecord::Base.establish_connection(
            :adapter => "mysql2",
            :host => "localhost",
            :database => "siteconfig_development",
            :username => "root",
            :password => "root123"
)

sql = "SELECT * from users"
@result = @connection.connection.execute(sql);
@result.each(:as => :hash) do |row| 
   puts row["email"] 
end

推荐答案

也许试试这个:

ActiveRecord::Base.establish_connection(...)
ActiveRecord::Base.connection.execute(...)

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