I create 3 models

class RealUnit(models.Model):
    _name = 'real.units'
    real_id = fields.Many2one('real.realstate', 'Real State', ondelete='cascade')
    unit_no = fields.Char('Unit No.')
    rented = fields.Boolean('Rented')

class RealContractUnit(models.Model):
    _name = 'real.contract_units'
    real_id = fields.Many2one('real.realstate', 'Real State', ondelete='restrict')
    unit_id = fields.Many2one('real.units', 'Unit', ondelete='restrict', domain="[('real_id', '=', real_id)]")

class RealContract(models.Model):
    _name = 'real.contracts'
    cont_no = fields.Char('Contract No.', index=True, search='_search_function',
                          filter_domain="[('cont_no','ilike',self)]", required=True)
    real_id = fields.Many2one('real.realstate', 'Real State.', ondelete='restrict', required=True)
    units = fields.One2many('real.contract_units', 'cont_id', 'Units')

I want update rented flag to set it false  for all units  deleted from one2many table in contract view 

I don't know if I can use unlike function to do it and how implement 

Thanks