Add ability to set the Record factory on the connection

[elprans]

In order to provide for alternative ways of accessing fields, or adding custom functionality, make it possible to specify a Record factory on a connection.

See #38 and #13 for related discussions.

[pmart123]

@elprans nice. Incorporating this issue is invaluable.

[Congee]

This is necessary not only for dot accessor wanted in #38 and #13. I don't know any way to elegantly convert json, uuid objects from postgres to python objects except thru monkey patching.

What I am doing now is ugly IMO.

[
    {
        **record,
        'task_id': str(record['task_id']),  # uuid to str
        'rates': json.loads(t['rates']),  # jsonb to dict
    }
    for record in fetched_records
]

The ability to use customized Record is a must, dude. It's been more than 2 years

[1st1]

The ability to use customized Record is a must, dude. It's been more than 2 years

Dear "dude", you're welcome to make a PR. Please make sure that the performance of asyncpg code that uses the builtin asyncpg.Record won't be impacted by it.

[Pirulax]

Hey,
Is there any related docs on how to exactly use these custom classes?
What are they for exactly?
How do they work?

I have a similar issue the guy above (the "dude"), so I wonder what the solution to it would be using record_class.
So far I understand that I need to subclass Record and pass that to every function as record_class, but that's it.
I'd like to have namedtuple-like access (so instead of rec['id']to haverec.id`) + type hinting.

Thanks!

[elprans]

You need to subclass Record, e.g.:

class MyRecord(asyncpg.Record):
    def __getattr__(self, name):
        return self[name]

and then

conn = await asyncpg.connect(..., record_class=MyRecord)

You can also specify a record_class per-query.

[Pirulax]

Okay I see.

I thought I could easily add typing to it too, but that doesn't seem to be the case.
So I'll just stick to the dataclass way I think.

(I'm using a connection pool btw)

[elprans]

You can actually add typing, though we need to land #577 to actually enable type checking.