You can do it by creating a new environment for another database.

Refer following sample code:

from odoo import api, models, registry, SUPERUSER_ID

class my_class(models.Model):

    @api.multi
    def get_data_from_database(self):
        with registry('another_database_name') as new_cr:
            env = api.Environment(new_cr, SUPERUSER_ID, {})
            partner = env['res.partner'].search([('name', '=', 'ERP HARBOR CONSULTING SERVICES')], limit=1)
            print partner.name, partner.phone

Hope this will help you.

Sudhir Arya
ERP Harbor Consulting Services
skype:	sudhir@erpharbor.com  website: http://www.erpharbor.com