There are three options available if you want to write new values to the fields of records:

• Option 1 is the one explained in the recipe, and it works in all contexts, assigning values directly on the attribute representing the field of the record. It is not possible to assign a value to all recordset elements in one go, so you need to iterate on the recordset, unless you are certain that you are only handling a single record.

• Option 2 is to use the update() method by passing a dictionary mapping field names to the values you want to set. This also only works for recordsets of length 1. It can save some typing when you need to update the values of several fields at once on the same record. Here's step 2 of the recipe, rewritten to use this option:

    @api.model 
    def add_contacts(self, partner, contacts): 
        partner.ensure_one() 
        if contacts: 
            today = fields.Date.context_today(self) 
            partner.update( 
                {'date': today, 
                 'child_ids': partner.child_ids | contacts} 
            ) 

• Option 3 is to call the write() method, passing a dictionary mapping field names to the values you want to set. This method works for recordsets of arbitrary size and will update all records with the specified values in one single database operation when the two previous options perform one database call per record and per field. However, it has some limitations:
  • It does not work if the records are not yet present in the database (refer to the Writing onchange methods recipe in Chapter 9, Advanced Server-Side Development Techniques, for more information on this)
  • It requires using a special format when writing relational fields, similar to the one used by the create() method: