Tindakan perpindahan basisdata

Semua operations ini tersedia dari modul django.contrib.postgres.operations.

Membuat tambahan menggunakan perpindahan

Anda dapat membuat tambahan PostgreSQL dalam basisdata anda menggunakan berkas pemindahan. Contoh ini membuat sebuah tambahan hstore, tetapi prinsip-prinsip sama berlaku untuk tambahan-tambahan lain.

Setel tambahan hstore dalam PostgreSQL sebelum tindakan pertama CreateModel atau AddField yang melibatkan HStoreField dengan menambahkan perpindahan dengan tindakan HStoreExtension. Sebagai contoh:

from django.contrib.postgres.operations import HStoreExtension


class Migration(migrations.Migration):
    ...

    operations = [HStoreExtension(), ...]

The operation skips adding the extension if it already exists.

For most extensions, this requires a database user with superuser privileges. If the Django database user doesn't have the appropriate privileges, you'll have to create the extension outside of Django migrations with a user that has them. In that case, connect to your Django database and run the query CREATE EXTENSION IF NOT EXISTS hstore;.

CreateExtension

class CreateExtension(name, hints=None)[sumber]

An Operation subclass which installs a PostgreSQL extension. For common extensions, use one of the more specific subclasses below.

name

Ini adalah argumen wajib. Nama dari tambahan untuk dipasang.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

BloomExtension

class BloomExtension(hints=None)[sumber]

Installs the bloom extension.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

BtreeGinExtension

class BtreeGinExtension(hints=None)[sumber]

Installs the btree_gin extension.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

BtreeGistExtension

class BtreeGistExtension(hints=None)[sumber]

Installs the btree_gist extension.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

CITextExtension

class CITextExtension(hints=None)[sumber]

Pasang tambahan citext.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

CryptoExtension

class CryptoExtension(hints=None)[sumber]

Pasang tambahan pgcrypto.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

HStoreExtension

class HStoreExtension(hints=None)[sumber]

Pasang tambahan hstore dan juga setel hubungan pada penterjemah data hstore untuk kemungkinan penggunaan dalam perpindahaan selanjutnya.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

TrigramExtension

class TrigramExtension(hints=None)[sumber]

Pasang tambahan pg_trm.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

UnaccentExtension

class UnaccentExtension(hints=None)[sumber]

Pasang tambahan unaccent.

hints

New in Django 6.0.

The optional hints argument will be passed as **hints to the allow_migrate() method of database routers to assist them in making routing decisions.

Managing collations using migrations

If you need to filter or order a column using a particular collation that your operating system provides but PostgreSQL does not, you can manage collations in your database using a migration file. These collations can then be used with the db_collation parameter on CharField, TextField, and their subclasses.

For example, to create a collation for German phone book ordering:

from django.contrib.postgres.operations import CreateCollation


class Migration(migrations.Migration):
    ...

    operations = [
        CreateCollation(
            "case_insensitive",
            provider="icu",
            locale="und-u-ks-level2",
            deterministic=False,
        ),
        ...,
    ]

class CreateCollation(name, locale, *, provider='libc', deterministic=True)[sumber]

Creates a collation with the given name, locale and provider.

Set the deterministic parameter to False to create a non-deterministic collation, such as for case-insensitive filtering.

class RemoveCollation(name, locale, *, provider='libc', deterministic=True)[sumber]

Removes the collations named name.

When reversed this is creating a collation with the provided locale, provider, and deterministic arguments. Therefore, locale is required to make this operation reversible.

Concurrent index operations

PostgreSQL supports the CONCURRENTLY option to CREATE INDEX and DROP INDEX statements to add and remove indexes without locking out writes. This option is useful for adding or removing an index in a live production database.

class AddIndexConcurrently(model_name, index)[sumber]

Like AddIndex, but creates an index with the CONCURRENTLY option. This has a few caveats to be aware of when using this option, see the PostgreSQL documentation of building indexes concurrently.

class RemoveIndexConcurrently(model_name, name)[sumber]

Like RemoveIndex, but removes the index with the CONCURRENTLY option. This has a few caveats to be aware of when using this option, see the PostgreSQL documentation.

Catatan

The CONCURRENTLY option is not supported inside a transaction (see non-atomic migration).

Adding constraints without enforcing validation

PostgreSQL supports the NOT VALID option with the ADD CONSTRAINT statement to add check constraints without enforcing validation on existing rows. This option is useful if you want to skip the potentially lengthy scan of the table to verify that all existing rows satisfy the constraint.

To validate check constraints created with the NOT VALID option at a later point of time, use the ValidateConstraint operation.

Lihat the PostgreSQL documentation untuk rincian lebih.

class AddConstraintNotValid(model_name, constraint)[sumber]

Like AddConstraint, but avoids validating the constraint on existing rows.

class ValidateConstraint(model_name, name)[sumber]

Scans through the table and validates the given check constraint on existing rows.

Catatan

AddConstraintNotValid and ValidateConstraint operations should be performed in two separate migrations. Performing both operations in the same atomic migration has the same effect as AddConstraint, whereas performing them in a single non-atomic migration, may leave your database in an inconsistent state if the ValidateConstraint operation fails.