All of these functions are available from the
django.contrib.postgres.functions module.
RandomUUID¶Returns a version 4 UUID.
The pgcrypto extension must be installed. You can use the
CryptoExtension migration
operation to install it.
Usage example:
>>> from django.contrib.postgres.functions import RandomUUID
>>> Article.objects.update(uuid=RandomUUID())
TransactionNow¶Returns the date and time on the database server that the current transaction
started. If you are not in a transaction it will return the date and time of
the current statement. This is a complement to
django.db.models.functions.Now, which returns the date and time of the
current statement.
Note that only the outermost call to atomic()
sets up a transaction and thus sets the time that TransactionNow() will
return; nested calls create savepoints which do not affect the transaction
time.
Usage example:
>>> from django.contrib.postgres.functions import TransactionNow
>>> Article.objects.filter(published__lte=TransactionNow())
<QuerySet [<Article: How to Django>]>
1月 11, 2019