for updating the record only I wrote

 business_funding.business_case_id.write({'business_funding_ids': funding_data})

but with this a new record is getting created in the DB
Please check the lead 2 values

Hi,
On quick check it seems you are adding data to one2many field and i believe it is working fine ? So instead of adding you need to update the existing one2many records right ? iF yes, you need to adjust the last lines of code

If its fine, how about clearing the current data in one2many and adding all again once ?

Thanks