在Ruby on Rails中动态连接到第二个MySQL数据库

Question

I'm working on a rails application that will migrate user content. I need to take in database parameters via a form and use them to connect to the given database. What's the best way to achieve this? I've attempted using Mysql.real_connect with no joy.

Answer 1

您可以拨打establish_connection用新的参数，然后用connection正常。

Answer 2

I had a similar need in a rake task. I ended up using basically the following code after the rails environment had been loaded by rake.

require "mysql2"

#Constants
#---------
DB_HOST = "example.com"
DB_USER = "username"
DB_PASSWORD = "password"
DB = "db_name"

SQL = "SELECT * FROM BLAH;"

client = Mysql2::Client.new(:host => DB_HOST, :username => DB_USER,
                            :password=> DB_PASSWORD, :database => DB)

rs = client.query(SQL)
rs.each do |h|
  #Work on Row here
end

It is using mysql (mainly because I got tired of mysql crashing the script), but the process should be the same.

Answer 3

Check ruby/mysql

require "mysql"
my = Mysql::new("host", "user", "passwd", "db")
res = my.query("select * from tbl")
res.each do |row|
  col1 = row[0]
  col2 = row[1]
end