Model

This class serves as the base for all database models, providing the core functionality for mapping Python objects to database tables. It handles instance initialization, state management, and lifecycle operations such as saving, deleting, and refreshing data from the database. The class also includes comprehensive validation logic for fields, unique constraints, and model-level consistency checks.

Attributes

Attribute	Type	Description
pk	property	Proxy property that provides access to the value of the model's primary key field.

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Constructor

Signature

def Model(
    *args: tuple,
    **kwargs: dict
) - > null

Parameters

Name	Type	Description
*args	tuple	Positional arguments used to initialize model fields in the order they are defined.
**kwargs	dict	Keyword arguments representing field names and their corresponding values for initialization.

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Methods

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from_db()

@classmethod
def from_db(
    db: str,
    field_names: list,
    values: list,
    fetch_mode: str = null
) - > [Model](model.md?sid=django_db_models_base_model)

Creates a model instance from database values, bypassing the standard constructor to handle deferred fields and database state.

Parameters

Name	Type	Description
db	str	The alias of the database the instance was loaded from.
field_names	list	The names of the fields being loaded from the database.
values	list	The raw values for the fields, in the order they appear in the model's concrete fields.
fetch_mode	str = null	The mode used to fetch the data, such as FETCH_ONE.

Returns

Type	Description
[Model](model.md?sid=django_db_models_base_model)	A new instance of the model populated with data from the database.

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get_deferred_fields()

@classmethod
def get_deferred_fields() - > set

Return a set containing names of deferred fields for this instance.

Returns

Type	Description
set	A set of attribute names for fields that have not yet been loaded from the database.

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refresh_from_db()

@classmethod
def refresh_from_db(
    using: str = null,
    fields: iterable = null,
    from_queryset: [QuerySet](../query/queryset.md?sid=django_db_models_query_queryset) = null
)

Reload field values from the database. By default, the reloading happens from the database this instance was loaded from.

Parameters

Name	Type	Description
using	str = null	The database alias to use for the reload; overrides the default router.
fields	iterable = null	An iterable of field attribute names to specifically reload.
from_queryset	[QuerySet](../query/queryset.md?sid=django_db_models_query_queryset) = null	A custom queryset to use for fetching the updated instance data.

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arefresh_from_db()

@classmethod
def arefresh_from_db(
    using: str = null,
    fields: iterable = null,
    from_queryset: [QuerySet](../query/queryset.md?sid=django_db_models_query_queryset) = null
) - > Coroutine

Asynchronously reload field values from the database by wrapping refresh_from_db.

Parameters

Name	Type	Description
using	str = null	The database alias to use for the reload.
fields	iterable = null	Specific field names to reload.
from_queryset	[QuerySet](../query/queryset.md?sid=django_db_models_query_queryset) = null	A custom queryset to use for the fetch.

Returns

Type	Description
Coroutine	A coroutine that completes the database refresh.

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serializable_value()

@classmethod
def serializable_value(
    field_name: str
) - > any

Return the value of the field name for this instance. If the field is a foreign key, return the id value instead of the object.

Parameters

Name	Type	Description
field_name	str	The name of the field whose serializable value is requested.

Returns

Type	Description
any	The raw field value or the primary key of a related object, suitable for serialization.

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save()

@classmethod
def save(
    force_insert: bool = false,
    force_update: bool = false,
    using: str = null,
    update_fields: iterable = null
)

Save the current instance. Override this in a subclass if you want to control the saving process.

Parameters

Name	Type	Description
force_insert	bool = false	If True, forces the save to perform an SQL INSERT.
force_update	bool = false	If True, forces the save to perform an SQL UPDATE.
using	str = null	The database alias to use for the save operation.
update_fields	iterable = null	An iterable of field names to update; if provided, only these fields are saved.

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asave()

@classmethod
def asave(
    force_insert: bool = false,
    force_update: bool = false,
    using: str = null,
    update_fields: iterable = null
) - > Coroutine

Asynchronously save the current instance to the database.

Parameters

Name	Type	Description
force_insert	bool = false	Forces an SQL INSERT.
force_update	bool = false	Forces an SQL UPDATE.
using	str = null	The database alias to use.
update_fields	iterable = null	Specific fields to update.

Returns

Type	Description
Coroutine	A coroutine that completes the save operation.

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delete()

@classmethod
def delete(
    using: str = null,
    keep_parents: bool = false
) - > tuple

Removes the current instance from the database and handles related object cleanup.

Parameters

Name	Type	Description
using	str = null	The database alias to use for the deletion.
keep_parents	bool = false	If True, prevents the deletion of parent model records in multi-table inheritance.

Returns

Type	Description
tuple	A tuple containing the total number of objects deleted and a dictionary with the count per object type.

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adelete()

@classmethod
def adelete(
    using: str = null,
    keep_parents: bool = false
) - > Coroutine

Asynchronously removes the current instance from the database.

Parameters

Name	Type	Description
using	str = null	The database alias to use.
keep_parents	bool = false	Whether to preserve parent model records.

Returns

Type	Description
Coroutine	A coroutine that completes the deletion.

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clean()

@classmethod
def clean()

Hook for doing any extra model-wide validation after clean() has been called on every field by self.clean_fields.

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validate_unique()

@classmethod
def validate_unique(
    exclude: iterable = null
)

Check unique constraints on the model and raise ValidationError if any failed.

Parameters

Name	Type	Description
exclude	iterable = null	A collection of field names to exclude from uniqueness checks.

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full_clean()

@classmethod
def full_clean(
    exclude: iterable = null,
    validate_unique: bool = true,
    validate_constraints: bool = true
)

Call clean_fields(), clean(), validate_unique(), and validate_constraints() on the model. Raise a ValidationError for any errors that occur.

Parameters

Name	Type	Description
exclude	iterable = null	Field names to skip during the cleaning process.
validate_unique	bool = true	Whether to perform uniqueness validation.
validate_constraints	bool = true	Whether to perform model constraint validation.

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clean_fields()

@classmethod
def clean_fields(
    exclude: iterable = null
)

Clean all fields and raise a ValidationError containing a dict of all validation errors if any occur.

Parameters

Name	Type	Description
exclude	iterable = null	Field names to exclude from individual field validation.

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check()

@classmethod
def check(
    kwargs: dict
) - > list

Runs system checks on the model to identify configuration errors, field clashes, or database incompatibilities.

Parameters

Name	Type	Description
kwargs	dict	Additional arguments for the check framework, such as 'databases'.

Returns

Type	Description
list	A list of check error and warning objects.

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