Sets the active connection to the specified key.
The previous database connection key.
public static final function setActiveConnection($key = 'default') {
if (empty(self::$databaseInfo)) {
self::parseConnectionInfo();
}
if (!empty(self::$databaseInfo[$key])) {
$old_key = self::$activeKey;
self::$activeKey = $key;
return $old_key;
}
}