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Metadata refers to a specific set of data that provides information about another data. In Django, we use Django models to design our database's tables and their fields. If we have to add some data about the model itself, we use classes. Learn more about classes Metain Django models in this article .Meta

MetaClasses in Django

MetaThe class is an inner class, which means it is defined inside the model as follows:

from django.db import models


class MyModel(models.Model):
    ...

    class Meta:
        ...

MetaClasses can be used to define various things about a model, such as permissions, database names, singular and plural names, abstractions, ordering, etc. Adding Metaclasses to a Django model is completely optional.

This class also comes with a number of options you can configure. Here are some commonly used meta options; you can explore all meta options here

Django meta options - summary

This option is used to define whether the model is abstract; they work the same way as abstract classes. Abstract classes are classes that cannot be instantiated, only extended or inherited.

Models set to abstract can only be inherited. This option can be used if there are multiple models with common fields.

from django.db import models


class Human(models.Model):
    genders = (
        ("M", "Male"),
        ("F", "Female"),
        ("NB", "Non-binary"),
        ("T", "Transgender"),
        ("I", "Intersex"),
        ("O", "Other"),
        ("PNTS", "Prefer not to say"),
    )

    name = models.CharField(max_length=200)
    age = models.IntegerField(default=0)
    gender = models.CharField(max_length=50, choices=genders)

    class Meta:
        abstract = True  # Important


class Teacher(Human):
    subject = models.CharField(max_length=200)


class Student(Human):
    grade = models.IntegerField(default=0)

Here, Teacherthe and Studentmodels will contain Humanall the fields from the model. In the database, only the Teacherand Studentmodels will be created.

Django meta options -db_table

This option is used to set the name used to identify the table within the database. For example: If I do the following, the name of my model will be in the database job.

from django.db import models


class JobPosting(models.Model):
    class Meta:
        db_table = "job"

Django meta options - sorting

This option takes a list of string values, which are the model fields. It is used to define the ordering of model objects. When objects of this model are retrieved, they will appear in this order.

from django.db import models


class JobPosting(models.Model):
    dateTimeOfPosting = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["-dateTimeOfPosting"]

In the example above, the retrieved objects will dateTimeOfPostingbe sorted in descending order based on the field. ( -The prefix is ​​used to define descending order.)

Django meta options -verbose_name

This option is used to define a human-readable singular name for the model, and will override Django's default naming convention. This name will also be reflected in the admin panel ( /admin/).

from django.db import models


class JobPosting(models.Model):
    class Meta:
        verbose_name = "Job Posting"

Django meta option - Verbose_name_plural

This option is used to define a human-readable plural name for the model, which again overrides Django's default naming convention. This name will also be reflected in the admin panel ( /admin/).

from django.db import models


class JobPosting(models.Model):
    class Meta:
        verbose_name_plural = "Job Postings"