Question

We are making a Ruby On Rails webapp where every customer gets their own database.
The database needs to be created after they fill out a form on our website.

We have a template database that has all of the tables and columns that we need to copy. How can I do this in programatically from ruby on rails?

Answer 1

From any controller, you can define the following method.

 def copy_template_database         template_name = 'customerdb1' # Database to copy from         new_name = 'temp' #database to create & copy to          #connect to template database to copy.  Note that this will override any previous         #connections for all Models that inherit from ActiveRecord::Base         ActiveRecord::Base.establish_connection({:adapter => 'mysql', :database => template_name, :host => 'olddev',         :username => 'root', :password => 'password' })          sql_connection = ActiveRecord::Base.connection          sql_connection.execute('CREATE DATABASE #{new_name} CHARACTER SET latin1 COLLATE latin1_general_ci')         tables = sql_connection.select_all('Show Tables')         #the results are an array of hashes, ie:         # [{'table_from_customerdb1' => 'customers'},{'table_from_customerdb1' => 'employees},...]         table_names = Array.new         tables.each { |hash| hash.each_value { |name| table_names << name }}          table_names.each { |name|              sql_connection.execute('CREATE TABLE #{new_name}.#{name} LIKE #{template_name}.#{name}')             sql_connection.execute('INSERT INTO #{new_name}.#{name} SELECT * FROM #{template_name}.#{name}')         }         #This statement is optional.  It connects ActiveRecord to the new database         ActiveRecord::Base.establish_connection({:adapter => 'mysql', :database => new_name, :host => 'olddev',         :username => 'root', :password => 'password' })     end 

Note that I do not know for sure if this will keep foriegn key integrity. I think it depends a lot on how the template Database is created.