Working with External Database

I think Drupal has pretty poor support when it comes to external data source.

I want to create a view which displays fields from external datasource tables. At first, the module: Views XML Backend seems to help me to solve the problem. But after installing this module, I realize that the module only you to select XML files from the same project folder. I would hope that that the module allows the views to parse web service in XML format from another server (or at least from another site on the same server). Also there is no equivalent module supporting JSON format.

Appreciate if anyone out there who has done something similar previously can give some advice.

Thanks