CODEWITHSUNDEEP
pythonpeewee
Jesus Benavent
Jesus Benavent

Reputation: 183

Reverse foreignkey query with peewee

I'm using the peewee orm and I would like to know how to do a reverse foreignkey query.

These are my models:

class Device(BaseModel):
    mac = CharField()
    ip = CharField()

class Metrics(BaseModel):
    device = ForeignKeyField(Device, related_name="metrics")
    sensor = CharField()
    analog = FloatField(null = True)
    timestamp = DateTimeField()

I would like to know the simplest way to get all the Devices that have a Metric with a field sensor="temperature".

I can solve it with various querys and some iteration, but I wonder if there is a more direct way to do it.

Thanks

Upvotes: 2

Views: 545

Answers (1)

coleifer
coleifer

Reputation: 26225

One way:

Device.select().join(Metric).where(Metric.sensor == 'temperature')

Another way:

Device.select().where(fn.EXISTS(
    Metric.select().where((Metric.sensor == 'temperature') & (Metric.device == Device.id))
))

Upvotes: 2

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