Hello Ra_one_1_11,

You can add sale_ids onchange to create a record or append to sale_orders.
Or add related in sale_order

for example: sale_orders = fields.Many2many("sale.order","booking_sale_rel","booking_id_rec","sale_id_rec",string="sale ids", related='sale_ids')

Thanks & Regards,
Email: odoo@aktivsoftware.com
Skype: kalpeshmaheshwari

Hi,

In your write function add as this:

def write(self, vals):
    for order in self.sale_ids:
        self.sale_orders = [(4, [order.id])]
    return super(BookingSchedule, self).write(vals)

For other options available with many2many field check this post: https://www.odoo.com/forum/help-1/many2many-write-replaces-all-existing-records-in-the-set-by-the-ids-148267

Thank you

i can't get any value in my second many2many fields 

lass bookingschedual(models.Model):

_name = "booking.schedule"

partner_id = fields.Many2one("res.partner", string="Customer")

sale_ids = fields.Many2many("sale.order", "sale_order_rel", "booking_id", "sale_id", string="Sale order")

sale_orders = fields.Many2many("sale.order","booking_sale_rel","booking_id_rec","sale_id_rec",string="sale ids",)

this is my code :

when i select res.partner in partner_id field then i got value of his sale order in sale_ids field 

now i want same value in sale_orders fields when i click on the save button 

i guess you are understand