How i can set value by another field model to model

Question

I have models

class Event(models.Model): some_field = models.CharField() class Ticket(models.Model): event = models.ForeignKey(Event)

How i can set model ticket field event, event with some_field field? Example:

Ticket.objects.create(event__some_field = 'value')

how can you achieve this?

ps. i can't use ticket.event_id = event_id and ticket.event = event in my situation (i don't want to request to database)

But at this point your ticket has not been linked to an event object in the first place, you will first need to assign one, for example with ticket.event = myevent. — willeM_ Van Onsem
– willeM_ Van Onsem, Commented May 1, 2019 at 9:35
Yes, I know, but let's say that I already have an event created, and I do not want to make a request for get event — Welis
– Welis, Commented May 1, 2019 at 9:39
Do you know the event_id of the event? If so you could set ticket.event_id=event_id(this will not make a "request" to the database). — Kristiyan Gospodinov
– Kristiyan Gospodinov, Commented May 1, 2019 at 10:07
ticket.event_id=event_id(this will not make a "request" to the database) - really? :( — Welis
– Welis, Commented May 1, 2019 at 10:12

Steve Jalim · Accepted Answer · 2019-05-01 09:38:32Z

2

You have to create and save the Event instance separate from creating the Ticket.

event = Event(some_field='value') event.save() ticket = Ticket() ticket.event = event ticket.save()

And if you wanted to update an already existing event related to a ticket:

ticket.event.some_field = "new value" ticket.event.save() # no need to save ticket here, because nothing has changed in the relationship between ticket and event

answered May 1, 2019 at 9:38

Steve Jalim

12.2k1 gold badge39 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Welis Over a year ago

i have been events when i create a ticket, just i don't want to make a request to database

Steve Jalim Over a year ago

Do you mean you already have the event instance? Or that you don't have it and you want to create a ticket for an event you don't hold in memory, but without hitting the DB?

Welis Over a year ago

no, i don't have event instance, but i have events in database

Welis Over a year ago

i don't want to make request to database for get event next create ticket

Welis Over a year ago

okey, i solved my problem, I am all like that need make request to database for get event before create ticket

|

Collectives™ on Stack Overflow

How i can set value by another field model to model

1 Answer 1

7 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Related