Database::getConnectionInfo in core/includes/database/database.inc

Gets information on the specified database connection.

Database::openConnection in core/includes/database/database.inc

Opens a connection to the server specified by the given key and target.

Database::renameConnection in core/includes/database/database.inc

Rename a connection and its corresponding connection information.

Database::setActiveConnection in core/includes/database/database.inc

Sets the active connection to the specified key.

install_database_errors in core/includes/install.core.inc

Checks a database connection and returns any errors.