Django compatibility

[frafra]

Jira Link: DB-2077
Hi!
as I use Django for many projects, I wanted to see if I could use YugabyteDB, so I decided to run the its test suite using YugabyteDB as a regular PostgresDB.

git clone --depth 1 https://github.com/django/django.git -b 3.0.4
cd django
cat << EOF > tests/test_yugabytedb.py
# Inspired by test_sqlite.py
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'postgres',
        'USER': 'postgres',
        'HOST': '127.0.0.1',
        'PORT': '5433',
    },
}
DATABASES['other'] = DATABASES['default']
SECRET_KEY = "django_tests_secret_key"
# Use a fast hasher to speed up tests.
PASSWORD_HASHERS = [
    'django.contrib.auth.hashers.MD5PasswordHasher',
]
EOF
tox -e py3-postgres -- --settings=test_yugabytedb

Here is what I get at the moment:

django.db.utils.NotSupportedError: INDEX on column of type 'INET' not yet supported

Some competitors offer a custom Django backend, but it would be even cooler to be able to use Django together with YugabyteDB without having to rely on external libraries and retaining a strong compatibility with Postgres.

Is this related with #1113?

[ddorian]

hi @frafra

Running the test suite there are these issues:

• Inet indexes are built on top of gist indexes. We have an open issue regarding this: [YSQL] Support GIN and GIST index methods #1337
• deferred foreign key since that's what Django Uses: [YSQL] DEFERRABLE constraint should be supported #1709
• DECLARE CURSOR [YSQL] "ERROR: Declare Cursor Variable not supported yet" stops me implementing my use-case #3286
• django.db.utils.NotSupportedError: PRIMARY KEY containing column of type 'INET' not yet supported
• django.db.utils.NotSupportedError: COLLATE not supported yet
  LINE 1: ...al NOT NULL PRIMARY KEY, "char_field" varchar(10) COLLATE "s... [YSQL] Feature Support - Column Collation #1127
• ALTER TABLE "auth_user" ALTER COLUMN "username" TYPE varchar(150); [YSQL] Add support for ALTER TABLE ALTER COLUMN TYPE #1013

Adding a custom driver seems interesting. It may not support all features but won't be blocking.

[rkarthik007]

• @nchandrappa as well who can help.

I decided to run the its test suite using YugabyteDB as a regular PostgresDB.

Thats an interesting approach! We should definitely shoot for that in the longer run. But more immediately, we may try to unblock the more common usage patterns of Django, for example the one regarding deferred foreign key, which comes up more commonly.

[rajaiswal]

django.db.utils.NotSupportedError: DEFERRABLE constraint not supported yet
LINE 1: ...type_id") REFERENCES "django_content_type" ("id") DEFERRABLE...
                                                             ^
HINT:  See https://github.com/YugaByte/yugabyte-db/issues/1129. Click '+' on the description to raise its priority

Linking the DEFERRABLE constraint error here mentioned in #1129 and #3987 so we can keep all Django related issues in one place.