如何在Rails应用程序中使用多个数据库使用database.yml [英] How to Use Multiple Databases in a Rails App Using the database.yml

问题描述

我已阅读有关如何执行此操作的文档，但在实践中，我遇到了问题。
在我的应用程序中，我有两个不同的数据库，如下所述在我的database.yml文件。

  sqlite_test：
 adapter：sqlite3 
 database：db / sqlite_test.sqlite3 
 table： plots 
 pool：5 
 timeout：5000 
 
开发：
适配器：mysql2 
编码：utf8 
 reconnect：false 
 database：test 
 pool：5 
 username：myname 
 password：mypassword 
 host：localhost 
  

我的应用程序是一个动态绘图仪，它将绘制（基本）数据库中的数据，而无需了解数据库中的内容或其结构。这两个数据库都包含不同的数据。我在一个单独的Rails应用程序中创建的SQLite数据库。

我使用的当前应用程序是围绕MYSQL数据库构建的。
我将SQLite数据库复制到/ db目录中。所以在我的主模型中，当我说：

  class Plot< ActiveRecord :: Base 
 
 establish_connection：development 
 set_table_namestock_test
 set_primary_key：id 
  

一切正常，只是罚款和dandy。但是，当我将其更改为：

  establish_connection：sqlite_test 
 set_table_nameplots
  

并尝试通过Rails控制台访问该数据库，我得到一个错误：

 >> ActiveRecord :: AdapterNotSpecified：数据库配置未指定适配器
  

我不知道为什么，因为database.yml文件清楚地指定一个适配器？
当我在我的模型手工做，但一切工作正如它应该。

  class Plot< ActiveRecord :: Base 
 establish_connection（：adapter =>sqlite3，：database =>db / sqlite_test.sqlite3，：pool => 5）
  
 
 
 
当我手动指定database.yml中的内容时，而不是当我只是使用database.yml引用时，为什么全部工作？
 
 
 
谢谢！ 
解决方案
我试图复制并让它工作。它与命名约定有关：
您处于开发模式，AR将寻找开发标记，在您的情况下，sqlite不存在。
 
 
 
这是我的database.yml：
 开发：
 adapter：mysql2 
数据库：se_development 
 username：root 
 pool：5 
 timeout：5000 
 
 sqlite_development：
 adapter：sqlite3 
 database：db / development.sqlite3 
 pool：5 
 timeout：5000 
  
以下是型号：
  class Plot< ActiveRecord :: Base 
 establish_connection'sqlite_'+ Rails.env 
 end 
  
为我工作。希望这有帮助。
 
I've read up on the documentation on how to do this, but in practice, I am having problems. 
In my app, I have 2 different databases as described below in my database.yml file.  
sqlite_test:
    adapter: sqlite3
    database: db/sqlite_test.sqlite3
    table: plots
    pool: 5
    timeout: 5000

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: test
  pool: 5
  username: myname
  password: mypassword
  host: localhost
My application is a dynamic plotter that will plot the data in a (basic) database without having knowledge of whats in the database, or how its structured. Both of these databases contain different data. The SQLite database I created in a separate Rails app.

The current app I'm using is built around the MYSQL database, which I build externally. 
I copied the SQLite database into the /db directory. So in my main model, when I say:
  class Plot < ActiveRecord::Base

  establish_connection :development
  set_table_name "stock_test"
  set_primary_key :id
Everything works out just fine and dandy. However, when I change it to:
 establish_connection :sqlite_test
 set_table_name "plots"
and try to access that database via the Rails console, I get an error saying:
>>ActiveRecord::AdapterNotSpecified: database configuration does not specify adapter
I don't know why that is, since the database.yml file clearly does specify an adapter?
When I do it by hand in my model though, everything works exactly as it should. 
class Plot < ActiveRecord::Base
establish_connection(:adapter => "sqlite3", :database => "db/sqlite_test.sqlite3", :pool => 5 )
Why does it all work when I manually specify whats in the database.yml, but not when I just use the database.yml reference?

Thanks! 
解决方案
I tried to replicate and got it to work. It has to do with naming conventions:
You're in development mode and AR will look for the development tag, which in your case does not exist for sqlite.

Here is my database.yml:
development:
  adapter: mysql2
  database: se_development
  username: root
  pool: 5
  timeout: 5000

sqlite_development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000
Here is the model:
class Plot < ActiveRecord::Base
  establish_connection 'sqlite_' + Rails.env
end
Worked for me. Hope this helps.

                        
这篇关于如何在Rails应用程序中使用多个数据库使用database.yml的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！