in where can i change the (res_model) and (res_id)

I added below code but odoo server error popup:

Record does not exist or has been deleted.

(Records: [204], User: 1)

rfq= self.env['purchase.order'].create({

'......':

'......':

})

attachment = self.env['ir.attachment'].search([('res_model','=','purchase.requisition'), ('res_id','=', self.id)])

self.env['ir.attachment'].create({

'name': attachment.name ,

'res_name': rfq.name,

'type': 'binary',

'datas': attachment.datas,

'res_model': 'purchase.order',

'res_id': rfq.id,

})

here you are creating new attachment. you should user write method instead of create

attachment.write({res_model': 'purchase.order', 'res_id': rfq.id,})

Thanks Ravi, Solved