From 344593893b6fc5fdda45a74013fc8622401c5058 Mon Sep 17 00:00:00 2001 From: sdolemelipone Date: Sat, 3 Dec 2022 11:14:57 +0000 Subject: [PATCH] Fixed #34199 -- Added example to StringAgg docs. --- docs/ref/contrib/postgres/aggregates.txt | 26 ++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/docs/ref/contrib/postgres/aggregates.txt b/docs/ref/contrib/postgres/aggregates.txt index d8964115e0..55ec952fa2 100644 --- a/docs/ref/contrib/postgres/aggregates.txt +++ b/docs/ref/contrib/postgres/aggregates.txt @@ -208,6 +208,32 @@ General-purpose aggregation functions Examples are the same as for :attr:`ArrayAgg.ordering`. + Usage example:: + + class Publication(models.Model): + title = models.CharField(max_length=30) + + class Article(models.Model): + headline = models.CharField(max_length=100) + publications = models.ManyToManyField(Publication) + + >>> article = Article.objects.create(headline="NASA uses Python") + >>> article.publications.create(title="The Python Journal") + + >>> article.publications.create(title="Science News") + + >>> from django.contrib.postgres.aggregates import StringAgg + >>> Article.objects.annotate( + ... publication_names=StringAgg( + ... "publications__title", + ... delimiter=", ", + ... ordering="publications__title", + ... ) + ... ).values("headline", "publication_names") + + .. deprecated:: 4.0 If there are no rows and ``default`` is not provided, ``StringAgg``