Catatan terbitan Django 2.0¶

Sintaksis perutean URL disederhanakan¶

Fungsi baru django.urls.path() mengizinkan lebih mudah, sintaksis perutean URL lebih dibaca. Sebagai contoh, contoh ini dari terbitan Django sebelumnya:

url(r"^articles/(?P<year>[0-9]{4})/$", views.year_archive),

dapat ditulis sebagai:

path("articles/<int:year>/", views.year_archive),

Sintaksis baru mendukung jenis paksaan parameter URL. Dalam contoh, tampilan akan menerima argumen katakunci year sebagai sebuah integer daripada sebuah string. Juga, URL yang akan cocok sedikit kurang dibatasi dalam penulisan kembali contoh. Sebagai contoh, tahun 10000 akan sekarang cocok karena tahun integer tidak dibatasi untuk menjadi tepat panjang empat angka ketika mereka berada di regular expression.

Fungsi django.conf.urls.url() dari versi sebelumnya sekarang tersedia sebagai django.urls.re_path(). Tempat lama tetap untuk kesesuaian kebelakang, tanpa sebuah pengusangan dekat. Fungsi lama django.conf.urls.include() sekarang dapat diimpor dari django.urls sehingga anda dapat menggunakan from django.urls import include, path, re_path dalam URLconf and.

Dokumen Pengirim URL ditulis kembali untuk ditampilkan sintaksis baru dan menyediakan lebih rinci.

contrib.admin ramah seluler¶

Admin sekarang bergantian dan mendukung semua perangkat seluler utama. Peramban lama mungkin mengalami tingkaran beragam dari pengurangan yang anggun.

Pernyataan Window¶

Pernyataan baru Window mengizinkan menambahkan sebuah klausa OVER pada queryset. Anda dapat menggunakan :ref:`window functions ` dan :ref:`aggregate functions ` dalam pernyataan.

Fitur kecil¶

Memindahkan dukungan untuk bytestring di beberapa tempat¶

To support native Python 2 strings, older Django versions had to accept both bytestrings and Unicode strings. Now that Python 2 support is dropped, bytestrings should only be encountered around input/output boundaries (handling of binary fields or HTTP streams, for example). You might have to update your code to limit bytestring usage to a minimum, as Django no longer accepts bytestrings in certain code paths. Python's -b option may help detect that mistake in your code.

For example, reverse() now uses str() instead of force_text() to coerce the args and kwargs it receives, prior to their placement in the URL. For bytestrings, this creates a string with an undesired b prefix as well as additional quotes (str(b'foo') is "b'foo'"). To adapt, call decode() on the bytestring before passing it to reverse().

API backend basisdata¶

Bagian ini menjelaskan perubahan yang mungkin diperlukan oleh backend basis data pihak ketiga.

• Metode DatabaseOperations.datetime_cast_date_sql(), datetime_cast_time_sql(), datetime_trunc_sql(), datetime_extract_sql(), dan date_interval_sql() sekarang hanya mengembalikan SQL untuk melakukan tindakan daripada SQL dan daftar parameter.

• Backend basisdata pihak-ketiga harus menambahkan atribut DatabaseWrapper.display_name dengan nama dari basisdata dimana backend anda bekerja dengannya. Django menggunakan itu dalam beragam pesan, seperti di pemeriksaan sistem.

• Argumen pertama SchemaEditor._alter_column_type_sql() sekarang model daripada table.

• Argumen pertama dari SchemaEditor._create_index_name() sekarang table_name daripada model.

• Untuk mengadakan dukungan FOR UPDATE OF, setel DatabaseFeatures.has_select_for_update_of = True. jika basisdata membutuhkan bahwa argumen menjadi kolom OF daripada tabel, setel DatabaseFeatures.select_for_update_of_column = True.

• Untuk mengadakan dukungan untuk pernyataan Window, setel DatabaseFeatures.supports_over_clause menjadi True. Anda mungkin butuh menyesuaikan metode DatabaseOperations.window_start_rows_start_end() dan/atau window_start_range_start_end().

• Backend basisdata pihak-ketiga harus menambahkan sebuah atribut DatabaseOperations.cast_char_field_without_max_length dengan jenis data basisdata yang akan digunakan dalam fungsi Cast untuk CharField jika argumen max_length tidak disediakan.

• The first argument of DatabaseCreation._clone_test_db() and get_test_db_clone_settings() is now suffix rather than number (in case you want to rename the signatures in your backend for consistency). django.test also now passes those values as strings rather than as integers.

• Third-party database backends should add a DatabaseIntrospection.get_sequences() method based on the stub in BaseDatabaseIntrospection.

Dijatuhkan dukungan untuk Oracle 11.2¶

The end of upstream support for Oracle 11.2 is Dec. 2020. Django 1.11 will be supported until April 2020 which almost reaches this date. Django 2.0 officially supports Oracle 12.1+.

Default MySQL isolation level is read committed¶

MySQL's default isolation level, repeatable read, may cause data loss in typical Django usage. To prevent that and for consistency with other databases, the default isolation level is now read committed. You can use the DATABASES setting to use a different isolation level, if needed.

max_length AbstractUser.last_name ditingkatkan menjadi 150¶

A migration for django.contrib.auth.models.User.last_name is included. If you have a custom user model inheriting from AbstractUser, you'll need to generate and apply a database migration for your user model.

Jika anda ingin menyediakan batasan 30 karakter untuk nama terakhir, gunakan formulir penyesuaian:

from django.contrib.auth.forms import UserChangeForm


class MyUserChangeForm(UserChangeForm):
    last_name = forms.CharField(max_length=30, required=False)

Jika anda berharap menjaga pembatasan ini dalam admin ketika mengubah pengguna, setel UserAdmin.form untuk menggunakan formulir ini:

from django.contrib.auth.admin import UserAdmin
from django.contrib.auth.models import User


class MyUserAdmin(UserAdmin):
    form = MyUserChangeForm


admin.site.unregister(User)
admin.site.register(User, MyUserAdmin)

QuerySet.reverse() dan last() terlarang setelah membelah¶

Calling QuerySet.reverse() or last() on a sliced queryset leads to unexpected results due to the slice being applied after reordering. This is now prohibited, e.g.:

>>> Model.objects.all()[:2].reverse()
Traceback (most recent call last):
...
TypeError: Cannot reverse a query once a slice has been taken.

Formulir bidang tidak lagi menerima argumen pilihan sebagai argumen penempatan¶

To help prevent runtime errors due to incorrect ordering of form field arguments, optional arguments of built-in form fields are no longer accepted as positional arguments. For example:

forms.IntegerField(25, 10)

memunculkan sebuah pengecualian dan harus diganti dengan:

forms.IntegerField(max_value=25, min_value=10)

call_command() mensahkan pilihan dia terima¶

call_command() now validates that the argument parser of the command being called defines all of the options passed to call_command().

For custom management commands that use options not created using parser.add_argument(), add a stealth_options attribute on the command:

class MyCommand(BaseCommand):
    stealth_options = ("option_name", ...)

Indeks-indeks tidak lagi menerima argumen penempatan¶

Sebagai contoh:

models.Index(["headline", "-pub_date"], "index_name")

memunculkan sebuah pengecualian dan harus diganti dengan:

models.Index(fields=["headline", "-pub_date"], name="index_name")

Batasan foreign key sekarang diadakan pada SQLite¶

This will appear as a backwards-incompatible change (IntegrityError: FOREIGN KEY constraint failed) if attempting to save an existing model instance that's violating a foreign key constraint.

Foreign keys are now created with DEFERRABLE INITIALLY DEFERRED instead of DEFERRABLE IMMEDIATE. Thus, tables may need to be rebuilt to recreate foreign keys with the new definition, particularly if you're using a pattern like this:

from django.db import transaction

with transaction.atomic():
    Book.objects.create(author_id=1)
    Author.objects.create(id=1)

Jika anda tidak membuat kembali foreign key sebagai DEFERRED, pertama-tama create() akan gagal sekarang dimana batasan foreign key dipaksakan.

Cadangkan basisdata anda dahulu! Setelah meningkatkan ke Django 2.0, anda dapat kemudian membangun kembali tabel-tabel menggunakan tulisan mirip ini:

from django.apps import apps
from django.db import connection

for app in apps.get_app_configs():
    for model in app.get_models(include_auto_created=True):
        if model._meta.managed and not (model._meta.proxy or model._meta.swapped):
            for base in model.__bases__:
                if hasattr(base, "_meta"):
                    base._meta.local_many_to_many = []
            model._meta.local_many_to_many = []
            with connection.schema_editor() as editor:
                editor._remake_table(model)

This script hasn't received extensive testing and needs adaption for various cases such as multiple databases. Feel free to contribute improvements.

In addition, because of a table alteration limitation of SQLite, it's prohibited to perform RenameModel and RenameField operations on models or fields referenced by other models in a transaction. In order to allow migrations containing these operations to be applied, you must set the Migration.atomic attribute to False.

Bermacam-macam¶

• Kelas SessionAuthenticationMiddleware dipindahkan. Itu tidak menyediakan kegunaan sejak autentifikasi sesi tanpa syarat ada di Django 1.10.

• The default HTTP error handlers (handler404, etc.) are now callables instead of dotted Python path strings. Django favors callable references since they provide better performance and debugging experience.

• RedirectView tidak lagi diam NoReverseMatch jika pattern_name tidak ada.

• When USE_L10N is off, FloatField and DecimalField now respect DECIMAL_SEPARATOR and THOUSAND_SEPARATOR during validation. For example, with the settings:

  USE_L10N = False
  USE_THOUSAND_SEPARATOR = True
  DECIMAL_SEPARATOR = ","
  THOUSAND_SEPARATOR = "."
  

  sebuah masukan dari "1.345" sekarang dirubah ke 1345 daripada 1.345.

• Subclasses of AbstractBaseUser are no longer required to implement get_short_name() and get_full_name(). (The base implementations that raise NotImplementedError are removed.) django.contrib.admin uses these methods if implemented but doesn't require them. Third-party apps that use these methods may want to adopt a similar approach.

• Pengaturan bentuk FIRST_DAY_OF_WEEK dan NUMBER_GROUPING sekarang dijaga sebagai integer dalam keluaran tampilan JavaScript dan JSON.

• assertNumQueries() now ignores connection configuration queries. Previously, if a test opened a new database connection, those queries could be included as part of the assertNumQueries() count.

• The default size of the Oracle test tablespace is increased from 20M to 50M and the default autoextend size is increased from 10M to 25M.

• To improve performance when streaming large result sets from the database, QuerySet.iterator() now fetches 2000 rows at a time instead of 100. The old behavior can be restored using the chunk_size parameter. For example:

  Book.objects.iterator(chunk_size=100)
  

• Providing unknown package names in the packages argument of the JavaScriptCatalog view now raises ValueError instead of passing silently.

• A model instance's primary key now appears in the default Model.__str__() method, e.g. Question object (1).

• makemigrations now detects changes to the model field limit_choices_to option. Add this to your existing migrations or accept an auto-generated migration for fields that use it.

• Performing queries that require automatic spatial transformations now raises NotImplementedError on MySQL instead of silently using non-transformed geometries.

• django.core.exceptions.DjangoRuntimeWarning dipindahkan. Itu hanya digunakan dalam backend cache sebagai sebuah kelas pertengahan dalam warisan CacheKeyWarning dari RuntimeWarning.

• Renamed BaseExpression._output_field to output_field. You may need to update custom expressions.

• In older versions, forms and formsets combine their Media with widget Media by concatenating the two. The combining now tries to preserve the relative order of elements in each list. MediaOrderConflictWarning is issued if the order can't be preserved.

• django.contrib.gis.gdal.OGRException is removed. It's been an alias for GDALException since Django 1.8.

• Dukungan GEOS 3.3.x dijatuhkan.

• The way data is selected for GeometryField is changed to improve performance, and in raw SQL queries, those fields must now be wrapped in connection.ops.select. See the Raw queries note in the GIS tutorial for an example.

Argumen context dari Field.from_db_value() dan Expression.convert_value()¶

The context argument of Field.from_db_value() and Expression.convert_value() is unused as it's always an empty dictionary. The signature of both methods is now:

(self, value, expression, connection)

dari pada:

(self, value, expression, connection, context)

Support for the old signature in custom fields and expressions remains until Django 3.0.

Bermacam-macam¶

• The django.db.backends.postgresql_psycopg2 module is deprecated in favor of django.db.backends.postgresql. It's been an alias since Django 1.9. This only affects code that imports from the module directly. The DATABASES setting can still use 'django.db.backends.postgresql_psycopg2', though you can simplify that by using the 'django.db.backends.postgresql' name added in Django 1.9.

• django.shortcuts.render_to_response() is deprecated in favor of django.shortcuts.render(). render() takes the same arguments except that it also requires a request.

• The DEFAULT_CONTENT_TYPE setting is deprecated. It doesn't interact well with third-party apps and is obsolete since HTML5 has mostly superseded XHTML.

• HttpRequest.xreadlines() is deprecated in favor of iterating over the request.

• The field_name keyword argument to QuerySet.earliest() and QuerySet.latest() is deprecated in favor of passing the field names as arguments. Write .earliest('pub_date') instead of .earliest(field_name='pub_date').