RemoveCollation

Remove a collation.

Attributes

Attribute	Type	Description
category	[OperationCategory](../../../db/migrations/operations/base/operationcategory.md?sid=django_db_migrations_operations_base_operationcategory) = OperationCategory.REMOVAL	The operational category used to classify this migration action as a removal operation.

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Methods

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database_forwards()

@classmethod
def database_forwards(
    app_label: string,
    schema_editor: [BaseDatabaseSchemaEditor](../../../db/backends/base/schema/basedatabaseschemaeditor.md?sid=django_db_backends_base_schema_basedatabaseschemaeditor),
    from_state: [ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate),
    to_state: [ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)
) - > null

Executes the collation removal on the database if the connection is PostgreSQL and migration is allowed.

Parameters

Name	Type	Description
app_label	string	The label of the application being migrated to determine migration eligibility.
schema_editor	[BaseDatabaseSchemaEditor](../../../db/backends/base/schema/basedatabaseschemaeditor.md?sid=django_db_backends_base_schema_basedatabaseschemaeditor)	The database abstraction layer used to execute the SQL commands for dropping the collation.
from_state	[ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)	The state of the project before the operation is applied.
to_state	[ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)	The state of the project after the operation is applied.

Returns

Type	Description
null	Nothing is returned; the method performs an in-place database schema modification.

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database_backwards()

@classmethod
def database_backwards(
    app_label: string,
    schema_editor: [BaseDatabaseSchemaEditor](../../../db/backends/base/schema/basedatabaseschemaeditor.md?sid=django_db_backends_base_schema_basedatabaseschemaeditor),
    from_state: [ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate),
    to_state: [ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)
) - > null

Reverts the removal by re-creating the collation in the database schema.

Parameters

Name	Type	Description
app_label	string	The label of the application being migrated to determine migration eligibility.
schema_editor	[BaseDatabaseSchemaEditor](../../../db/backends/base/schema/basedatabaseschemaeditor.md?sid=django_db_backends_base_schema_basedatabaseschemaeditor)	The database abstraction layer used to execute the SQL commands for creating the collation.
from_state	[ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)	The state of the project before the reversal.
to_state	[ProjectState](../../../db/migrations/state/projectstate.md?sid=django_db_migrations_state_projectstate)	The state of the project after the reversal.

Returns

Type	Description
null	Nothing is returned; the method restores the previous database state.

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describe()

@classmethod
def describe() - > string

Returns a human-readable string describing the collation removal operation for migration logs.

Returns

Type	Description
string	A formatted string containing the name of the collation being removed.

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migration_name_fragment()

@classmethod
def migration_name_fragment() - > string

Generates a lowercase string fragment used to automatically name the migration file.

Returns

Type	Description
string	A snake_case string identifying the operation and the specific collation name.

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