As said by @nbessi, you have to define fnct_search which will let you do what you want. By definition, you can't store a one2many, it doesn't make any sense.

Hello.

Please try this:

The function related, must always return an iterable, if in some case it can return None it will explode,

If you try a Python console:

>>> None[1]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object has no attribute '__getitem__'
>>>

See, i'm obtaining almost the same error becasue the ORM is not capable to manage a value of a type different to what it is specting, can you try and tell me the result.

Regards.

BTW: It should be cool if you can share branch wih your module to see all the py file, regards.

I had edit this syntax to :

'user_ids': fields.function(
        _get_marche_users, string='Chefs',
        type='one2many', readonly=True,
        relation='res.users', multi='marche_users',
        fnct_search=_users_search)

the function _get_marche_users get users ids by intelligence and it works.

I know that the function _users_search must return this syntax :

[('id','in',res)]

and res is a list

I formulate now the question : res is it the table of ids of users that returned by the function _get_marche_users ? Really I need a full example, I grep the code and I have a big problem in a interresting project I don't found the documentation, just the prototype that's not sufficient, and I can't understand the source code so a help please I will be so grateful for you