iam trying to add scheduled action to add leave allocation for each employee who dose not  have running leave 

i make the below script 

class scheduler_demo(models.Model):
    _name = 'scheduler.demo'


    def _daily_leaves(self):

        test = self.env['hr.employee'].sudo().search([])
        for t in test.ids:
            holidays = self.env['hr.employee'].sudo().search([
                ('id', '=', t),
                ('current_leave_id', '=', '1')
            ])
            for line in holidays.ids:
                leave = self.env['hr.holidays'].create({
                    'employee_id': line,
                    'holiday_status_id': '1',
                    'type': 'add',
                    'holiday_type': 'employee',
                    'number_of_days_temp': '8'
                })
                leave.action_approve()
                if leave.double_validation:
                    leave.action_validate()
i received the below error

2019-01-19 09:26:31,848 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:31,957 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,081 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,193 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,302 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,440 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,549 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,665 26852 ERROR test4q odoo.osv.expression: Non-stored field hr.employee.current_leave_id cannot be searched.
2019-01-19 09:26:32,835 26852 INFO test4q werkzeug: 127.0.0.1 - - [19/Jan/2019 09:26:32] "POST /web/dataset/call_button HTTP/1.1" 200 -
2019-01-19 09:26:32,865 26852 INFO test4q werkzeug: 127.0.0.1 - - [19/Jan/2019 09:26:32] "POST /web/dataset/call_kw/ir.cron/search_read HTTP/1.1" 200 -
2019-01-19 09:26:33,163 26852 INFO test4q werkzeug: 127.0.0.1 - - [19/Jan/2019 09:26:33] "POST /web/menu/load_needaction HTTP/1.1" 200 -
2019-01-19 09:26:33,184 26852 INFO test4q werkzeug: 127.0.0.1 - - [19/Jan/2019 09:26:33] "POST /web/dataset/search_read HTTP/1.1" 200 -
2019-01-19 09:26:35,098 26852 INFO ? odoo.addons.bus.models.bus: Bus.loop listen imbus on db postgres