CODEWITHSUNDEEP
pythondjangodjango-modelsdjango-1.7
user1261774
user1261774

Reputation: 3695

django models.py ordering using foreign field

I am using django1.7 and I have two models.

One of my models I would like to specify the ordering by a field on a foreign model. The two models are linked by a foreign key.

Here are my two example models:

class ObjectiveDetails(models.Model, FillableModelWithLanguageVersion):
    user = models.ForeignKey(User)
    language_version = models.ForeignKey('LanguageVersion')
    field = models.TextField(null=False, blank=False, max_length=5000)
    objective_timestamp_added = models.DateTimeField(auto_now_add=True, auto_now=False)
    objective_timestamp_updated = models.DateTimeField(auto_now=True, auto_now_add=False)

    class Meta:
        ordering = ['language_version.language_code', 'id']

class LanguageVersion(models.Model):
    """Language version selection for a user"""
    user = models.ForeignKey(User)
    language_code = models.CharField(max_length=32)
    language_code_disabled = models.BooleanField(default=False)
    language_version_timestamp_added = models.DateTimeField(auto_now_add=True, auto_now=False)
    language_version_timestamp_updated = models.DateTimeField(auto_now=True, auto_now_add=False)  # the date the language version is updated when the user changes their subscription type.

I am trying to order the ObjectiveDetails by the language_code on the LanguageVersion model.

I have tried several attempts, but I cannot get it right. I have read the docs and searched SO & Google, but could not find the correct answer,

Upvotes: 2

Views: 484

Answers (1)

demonno
demonno

Reputation: 524

add ordering by language_code to LanguageVersion and remove .language_code from ObjectiveDetails

Each foreign key you add will implicitly include all of its default orderings as well.

https://docs.djangoproject.com/en/1.7/ref/models/options/#ordering

your models will be like this

class ObjectiveDetails(models.Model, FillableModelWithLanguageVersion):
    user = models.ForeignKey(User)
    language_version = models.ForeignKey('LanguageVersion')
    field = models.TextField(null=False, blank=False, max_length=5000)
    objective_timestamp_added = models.DateTimeField(auto_now_add=True, auto_now=False)
    objective_timestamp_updated = models.DateTimeField(auto_now=True, auto_now_add=False)

    class Meta:
        ordering = ['language_version', 'id']

class LanguageVersion(models.Model):
    """Language version selection for a user"""
    user = models.ForeignKey(User)
    language_code = models.CharField(max_length=32)
    language_code_disabled = models.BooleanField(default=False)
    language_version_timestamp_added = models.DateTimeField(auto_now_add=True, auto_now=False)
    language_version_timestamp_updated = models.DateTimeField(auto_now=True, auto_now_add=False)  # the date the language version is updated when the user changes their subscription type.

    class Meta:
        ordering = ['language_code']

Upvotes: 3

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