How to change the database for a connection?

Question

I'am developing some Ruby scripts which work with MySQL databases. All the databases are on one server. Unfortunately, we have a lot of databases (one for every costumer) and some scripts need to connect to each of those databases.

Right now, the scripts connect to some database using

db = Sequel.connect(:adapter => 'mysql', :user => user, :host => server, :database => database, :password => passwd, :encoding => 'utf8')

which works, but needs to disconnect and reconnect for each of those databases.

Is there a way of how to connect once to database server and then just change the database I'am working with?

Answer 1

You can probably do something like this if you really want to avoid disconnecting and reconnecting:

db = Sequel.connect(:adapter => 'mysql', :user => user, :host => server, :database => database, :password => passwd, :encoding => 'utf8', :single_threaded=>true)
databases = %w'db1 db2 db3'
databases.each do |db_name|
  db << "USE #{db_name}"
  ...
end

I'm not sure I'd recommend it unless the disconnecting and reconnecting was very slow (high latency between database and application?).