Rails Rails 4 指定第二个数据库，如何执行 migration?
配置如下
default: &default
adapter: mysql2
encoding: utf8
reconnect: false
pool: 5
username: root
host: remote_ip
port: 3306
development:
<<: *default
database: test
# 本地数据库
test2:
adapter: mysql2
encoding: utf8
reconnect: false
database: test2
pool: 5
username: root
password:
- 创建数据库：rake db:create RAILS_ENV=market
- 表迁移：rake db:migrate SRCDIR=test2_db/migrate/ RAILS_ENV=test2 第二步出现以下问题，记得在 rails3 里面这样做是可以的 ``` config.eager_load is set to nil. Please update your config/environments/*.rb files accordingly:
- development - set it to false
- test - set it to false (unless you use a tool that preloads your test environment)
- production - set it to true ```
class YourMigrationFile < ActiveRecord::Migration
def connection
@connection ||= ActiveRecord::Base.establish_connection("custom_db_#{Rails.env}").connection
end
def change
add_column :table, :column, :type
# reset connection
@connection = ActiveRecord::Base.establish_connection("#{Rails.env}").connection
end
end
@yangxing_star 你需要 migrate 到 custom_db 的需要加，如果比较多可以抽取一下。正常的 migration 文件无需改动。