|
| 1 | +- case: prefetch_related_to_attr |
| 2 | + main: | |
| 3 | + from myapp.models import Article, Tag |
| 4 | + from django.db.models import Prefetch |
| 5 | + from django.db import models |
| 6 | +
|
| 7 | + # Noop (to_attr not provided) |
| 8 | + reveal_type(Article.objects.prefetch_related(Prefetch("tags")).all()) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article, myapp.models.Article]" |
| 9 | + reveal_type(Article.objects.prefetch_related(Prefetch("tags", Tag.objects.all())).all()) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article, myapp.models.Article]" |
| 10 | +
|
| 11 | + # On the QuerySet |
| 12 | + article_qs = Article.objects.all().prefetch_related(Prefetch("tags", Tag.objects.all(), to_attr="every_tags")) |
| 13 | + reveal_type(article_qs) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})], myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})]]" |
| 14 | + reveal_type(article_qs.get().every_tags) # N: Revealed type is "builtins.list[myapp.models.Tag]" |
| 15 | + reveal_type( |
| 16 | + Tag.objects.all().prefetch_related( # N: Revealed type is "builtins.list[myapp.models.Article]" |
| 17 | + Prefetch("article_set", Article.objects.all(), to_attr="every_articles") |
| 18 | + ).get().every_articles |
| 19 | + ) |
| 20 | +
|
| 21 | + # On the Manager |
| 22 | + reveal_type( |
| 23 | + Article.objects.prefetch_related( # N: Revealed type is "builtins.list[myapp.models.Tag]" |
| 24 | + Prefetch("tags", Tag.objects.all(), to_attr="every_tags") |
| 25 | + ).get().every_tags |
| 26 | + ) |
| 27 | + reveal_type( |
| 28 | + Tag.objects.prefetch_related( # N: Revealed type is "builtins.list[myapp.models.Article]" |
| 29 | + Prefetch("article_set", Article.objects.all(), to_attr="every_articles") |
| 30 | + ).get().every_articles |
| 31 | + ) |
| 32 | +
|
| 33 | + # Member expr |
| 34 | + reveal_type( |
| 35 | + Article.objects.prefetch_related( # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})], myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})]]" |
| 36 | + models.Prefetch("tags", Tag.objects.all(), to_attr="every_tags") |
| 37 | + ).all() |
| 38 | + ) |
| 39 | + # pos args only |
| 40 | + reveal_type( |
| 41 | + Article.objects.prefetch_related( # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})], myapp.models.Article@AnnotatedWith[TypedDict({'every_tags': builtins.list[myapp.models.Tag]})]]" |
| 42 | + models.Prefetch("tags", Tag.objects.all(), "every_tags") |
| 43 | + ).all() |
| 44 | + ) |
| 45 | +
|
| 46 | + # Multiple Prefetch items: both `to_attr` annotations should be present |
| 47 | + multi_qs = Article.objects.all().prefetch_related( |
| 48 | + Prefetch("tags", Tag.objects.all(), to_attr="ts"), |
| 49 | + Prefetch("tags", Tag.objects.all(), to_attr="ts2"), |
| 50 | + ) |
| 51 | + reveal_type(multi_qs) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'ts': builtins.list[myapp.models.Tag], 'ts2': builtins.list[myapp.models.Tag]})], myapp.models.Article@AnnotatedWith[TypedDict({'ts': builtins.list[myapp.models.Tag], 'ts2': builtins.list[myapp.models.Tag]})]]" |
| 52 | + reveal_type(multi_qs.get().ts) # N: Revealed type is "builtins.list[myapp.models.Tag]" |
| 53 | + reveal_type(multi_qs.get().ts2) # N: Revealed type is "builtins.list[myapp.models.Tag]" |
| 54 | +
|
| 55 | + # Mixed inline `Prefetch` and plain lookup string in one call; string should be ignored |
| 56 | + mixed_plain = Article.objects.prefetch_related( |
| 57 | + "article_set", |
| 58 | + Prefetch("article_set", Article.objects.all(), to_attr="arts3"), |
| 59 | + ) |
| 60 | + reveal_type(mixed_plain) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'arts3': builtins.list[myapp.models.Article]})], myapp.models.Article@AnnotatedWith[TypedDict({'arts3': builtins.list[myapp.models.Article]})]]" |
| 61 | +
|
| 62 | +
|
| 63 | + ## Not Supported |
| 64 | +
|
| 65 | + # Prefetch with `to_attr` arg but without the `queryset` arg |
| 66 | + # TODO: We should be able to resolve a more accurate type using existing lookup `resolve_lookup_expected_type` machinery |
| 67 | + reveal_type(Article.objects.prefetch_related(models.Prefetch("tags", to_attr="just_tags")).get().just_tags) # N: Revealed type is "builtins.list[Any]" |
| 68 | +
|
| 69 | + # Intermediary variable -- function scope |
| 70 | + def foo() -> None: |
| 71 | + tag_prefetch = Prefetch("tags", Tag.objects.all(), to_attr="every_tags") |
| 72 | + reveal_type(Article.objects.prefetch_related(tag_prefetch).all()) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article, myapp.models.Article]" |
| 73 | +
|
| 74 | + # Intermediary variable -- module scope |
| 75 | + tag_prefetch = Prefetch("tags", Tag.objects.all(), to_attr="every_tags") |
| 76 | + reveal_type(Article.objects.prefetch_related(tag_prefetch).all()) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article, myapp.models.Article]" |
| 77 | +
|
| 78 | + # Mixed inline `Prefetch` and variable `Prefetch` in one call |
| 79 | + mixed_qs = Article.objects.prefetch_related( |
| 80 | + tag_prefetch, |
| 81 | + Prefetch("article_set", Article.objects.all(), to_attr="arts2"), |
| 82 | + ) |
| 83 | + reveal_type(mixed_qs) # N: Revealed type is "django.db.models.query.QuerySet[myapp.models.Article@AnnotatedWith[TypedDict({'arts2': builtins.list[myapp.models.Article]})], myapp.models.Article@AnnotatedWith[TypedDict({'arts2': builtins.list[myapp.models.Article]})]]" |
| 84 | +
|
| 85 | + installed_apps: |
| 86 | + - myapp |
| 87 | + files: |
| 88 | + - path: myapp/__init__.py |
| 89 | + - path: myapp/models.py |
| 90 | + content: | |
| 91 | + from django.db import models |
| 92 | +
|
| 93 | + class Tag(models.Model): ... |
| 94 | + class Article(models.Model): |
| 95 | + tags = models.ManyToManyField(to=Tag, related_name="articles", blank=True) |
| 96 | +
|
| 97 | +- case: prefetch_related_and_annotate |
| 98 | + main: | |
| 99 | + from django.db.models import Prefetch, F |
| 100 | + from django.contrib.auth.models import User, Group |
| 101 | +
|
| 102 | + user = ( |
| 103 | + User.objects |
| 104 | + .annotate(annotated_user=F("username")) |
| 105 | + .prefetch_related(Prefetch("groups", Group.objects.all(), to_attr="to_attr_groups")) |
| 106 | + .get() |
| 107 | + ) |
| 108 | + reveal_type(user.annotated_user) # N: Revealed type is "Any" |
| 109 | + reveal_type(user.to_attr_groups) # N: Revealed type is "builtins.list[django.contrib.auth.models.Group]" |
| 110 | +
|
| 111 | + installed_apps: |
| 112 | + - django.contrib.auth |
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