Snowflake backend for Django

Install and usage

Use the version of django-snowflake that corresponds to your version of
Django. For example, to get the latest compatible release for Django 6.0.x:

pip install django-snowflake==6.0.*

The minor release number of Django doesn't correspond to the minor release
number of django-snowflake. Use the latest minor release of each.

Configure the Django DATABASES setting similar to this:

DATABASES = {
    'default': {
        'ENGINE': 'django_snowflake',
        'NAME': 'MY_DATABASE',
        'SCHEMA': 'MY_SCHEMA',
        'WAREHOUSE': 'MY_WAREHOUSE',
        'USER': 'my_user',
        'PASSWORD': 'my_password',
        'ACCOUNT': 'my_account',
        # Include 'OPTIONS' if you need to specify any other
        # snowflake.connector.connect() parameters, documented at:
        # https://docs.snowflake.com/en/user-guide/python-connector-api.html#connect
        'OPTIONS': {
            # Examples:
            'role': 'MY_ROLE',
            # To use native Okta authenticators:
            # https://docs.snowflake.com/en/user-guide/admin-security-fed-auth-use#native-sso-okta-only
            'authenticator': 'https://example.okta.com',
            # To use private key authentication:
            'private_key_file': '<path>/rsa_key.p8',
            'private_key_file_pwd': 'my_passphrase',
        },
    },
}

Persistent connections

To use persisent connections, set Django's CONN_MAX_AGE
and Snowflake Python Connector's client_session_keep_alive:

DATABASES = {
    'default': {
        # ...
        'CONN_MAX_AGE': None,
        'OPTIONS': {
            'client_session_keep_alive': True,
        },
    },
}

Notes on Django fields

Consistent with Snowflake's convention,
this backend uppercases all database identifiers (table names, column names,
etc.) unless they are quoted, e.g. db_table='"table_name"'.
Snowflake supports defining foreign key and unique constraints, however, it
doesn't enforce them. Thus, Django manages these constraints and inspectdb
detects them, but Django won't raise IntegrityError if they're violated.
Snowflake doesn't support indexes. Thus, Django ignores any indexes defined
on models or fields.
Snowflake doesn't support check constraints, so the various
PositiveIntegerField model fields allow negative values (though validation
at the form level still works).

Notes on Django QuerySets

Snowflake has
limited support for subqueries.
Valid values for QuerySet.explain()'s format parameter are 'json',
'tabular', and 'text'. The default is 'tabular'.

Known issues and limitations

This list isn't exhaustive. If you run into a problem, consult
django_snowflake/features.py to see if a similar test is skipped. Please
create an issue on GitHub
if you encounter an issue worth documenting.

Snowflake doesn't support last_insert_id to retrieve the ID of a newly
created object. Instead, this backend issues the query
SELECT MAX(pk_name) FROM table_name to retrieve the ID. This is subject
to race conditions if objects are created concurrently. This makes this
backend inappropriate for use in web app use cases where multiple clients
could be creating objects at the same time. Further, you should not manually
specify an ID (e.g. MyModel(id=1)) when creating an object.
Due to snowflake-connector-python's lack of VARIANT support,
some JSONField queries with complex JSON parameters don't work.

For example, if value is a JSONField, this won't work:
```
>>> JSONModel.objects.filter(value__k={"l": "m"})
```
A workaround is:
```
>>> from django.db.models.expressions import RawSQL
>>> JSONModel.objects.filter(value__k=RawSQL("PARSE_JSON(%s)", ('{"l": "m"}',)))
```
In addition, QuerySet.bulk_update() isn't supported for JSONField.
Interval math where the interval is a column
is not supported.
Interval math with a null interval
crashes.

Troubleshooting

Debug logging

To troubleshoot issues with connectivity to Snowflake, you can enable
Snowflake Connector for Python's logging
using Django's LOGGING setting.

This is a minimal addition to Django's default "loggers" configuration that
enables the connector's DEBUG logging:

LOGGING = {
    …
    "loggers": {
        …
        "snowflake.connector": {
            "level": "DEBUG",
            "handlers": ["console"],
        },
    },
}

README