Rails中的多个数据库连接
我正在使用active_delegate在Rails中进行多个连接。 这里我使用mysql作为master_database用于某些模型，而postgresql用于其他一些模型。
问题是，当我尝试访问mysql模型时，我收到以下错误！ 堆栈跟踪显示，它仍然使用postgresql适配器来访问我的mysql模型！
RuntimeError: ERROR C42P01 Mrelation "categories" does not exist P15 F.\src\backend\parser\parse_relation.c L886 RparserOpenTable: SELECT * FROM "categories" STACKTRACE =========== d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract_adapter.rb:212:in `log' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/postgresql_adapter.rb:507:in `execute' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/postgresql_adapter.rb:985:in `select_raw' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/postgresql_adapter.rb:972:in `select' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all_without_query_cache' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/query_cache.rb:60:in `select_all' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/query_cache.rb:81:in `cache_sql' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/query_cache.rb:60:in `select_all' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:661:in `find_by_sql' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:1553:in `find_every' d:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:615:in `find' D:/ROR/Aptana/dedomenon/app/models/category.rb:50:in `get_all_with_exclusive_scope' D:/ROR/Aptana/dedomenon/app/models/category.rb:50:in `get_all_with_exclusive_scope' D:/ROR/Aptana/dedomenon/app/controllers/categories_controller.rb:48:in `index' 这是我的database.yml文件
postgre: &postgre adapter: postgresql database: codex host: localhost username: postgres password: root port: 5432 mysql: &mysql adapter: mysql database: project host: localhost username: root password: root port: 3306 development: <<: *postgre test: <<: *postgre production: <<: *postgre master_database: <<: *mysql
我的master_database模型是这样的
class Category [:create, :save, :destroy] end
有人有任何解决方案？
其他方式：
class Abc < ActiveRecord::Base establish_connection Rails.configuration.database_configuration["test"] end
现在可能想看看https://github.com/tchandy/octopus 。
这将更改单个模型对象的数据库连接。
$config = YAML.load_file(File.join(File.dirname(__FILE__), '../config/database.yml')) class ModelWithDifferentConnection < ActiveRecord::Base establish_connection $config['connection_name_from_database_yml'] end
如果您使用相同的服务器但只使用不同的数据库文件，那么您可以执行类似的操作。
class ModelWithDifferentConnection < ActiveRecord::Base # Lives in the CURRICULUM database def self.table_name "database.table" end end
我强烈建议使用MySQL适配器的MyReplication插件，它可以帮助您以优雅的方式在运行时切换连接：
User.using(:another_database) do u = User.all end
我试过你的Sample，仍然收到错误!!
superclass mismatch for class MysqlAdapter
我想，问题出在我的database.yml文件中。请检查此文件
database_mysql: adapter: mysql database: project host: localhost username: root password: root port: 3306 development: adapter: postgresql database: codex host: localhost username: postgres password: root port: 5432 test: adapter: postgresql database: codex host: localhost username: postgres password: root port: 5432 production: adapter: postgresql database: codex host: localhost username: postgres password: root port: 5432
我只在开发模式下启动杂种。
这是我的模型超类
$config = YAML.load_file(File.join(File.dirname(__FILE__), '../../config/database.yml')) class MasterDatabase < ActiveRecord::Base self.abstract_class = true establish_connection $config['database_mysql'] end
请纠正我..
我还必须连接并管理两个不同的数据库，所以我创建了一个名为secondbase的gem： http ：//github.com/karledurante/secondbase
我不知道active_delegate，但我最近不得不访问工作应用程序的不同数据库，并没有什么真正适合我想要的。 所以我为自己写了一些东西，它就像我们说的那样在生产应用程序中运行。
固定链接connection_ninja