from openerp import models, fields,api,http,SUPERUSER_ID class Chairs(models.Model): _name = 'salon.chair' name = fields.Char() related_employee = fields.Many2one('hr.employee', string='Related Employee') _sql_constraints = [ ('name_unique', 'unique(name)', 'This chair is already exist !'), ('related_employee_unique', 'unique(related_employee)', 'This person was reserved for another chair !')]