title: OpenERP 7 _constraints
body: <pre><code>class deduction_registration(osv.osv):
      _name = "bpl.deduction.registration"
      _description = "Deduction Registration"
      _columns = {
          'name': fields.char('Deduction Name', size=256, required=True),
      }
      _sql_constraints = [('deduction_registration_name_unique', 'unique(name)', 'Deduction name already exists')]
  
  deduction_registration()
  </code></pre>
  
  <p>I created above sql constraints for my model.but its still allow duplicate records without case sensitive.</p>
  
  <p>like <strong>EPF</strong> and <strong>epf</strong> allowed
  how to add constraint for that.?</p>