Multiple DB connection class

Question

How do you create multiple DB connections using Singleton pattern? Or maybe there's better approach, to share the same class but multiple connections?

Answer 1

How about using a Factory pattern to return the same instance for each connection, e.g.

ConnectionFactory::getInstance(ConnectionFactory::DEVELOPMENT);

Returns a Connection instance for a connection to the development database.

Instantiation of the Connection should only be performed by the ConnectionFactory, which can keep references to those instances in a static array, keyed by the connection type. This avoid the singleton pattern, but ensures you only maintain a single instance of each Connection.