fix inherited pk and add field accessor access to relations

This commit is contained in:
collerek
2021-06-25 13:32:31 +02:00
parent cc76e9b862
commit 107404c3e8
10 changed files with 516 additions and 61 deletions

View File

@ -169,20 +169,37 @@ async def delete():
async def joins():
# Tho join two models use select_related
# Django style
book = await Book.objects.select_related("author").get(title="The Hobbit")
# Python style
book = await Book.objects.select_related(Book.author).get(
Book.title == "The Hobbit"
)
# now the author is already prefetched
assert book.author.name == "J.R.R. Tolkien"
# By default you also get a second side of the relation
# constructed as lowercase source model name +'s' (books in this case)
# you can also provide custom name with parameter related_name
# Django style
author = await Author.objects.select_related("books").all(name="J.R.R. Tolkien")
# Python style
author = await Author.objects.select_related(Author.books).all(
Author.name == "J.R.R. Tolkien"
)
assert len(author[0].books) == 3
# for reverse and many to many relations you can also prefetch_related
# that executes a separate query for each of related models
# Django style
author = await Author.objects.prefetch_related("books").get(name="J.R.R. Tolkien")
# Python style
author = await Author.objects.prefetch_related(Author.books).get(
Author.name == "J.R.R. Tolkien"
)
assert len(author.books) == 3
# to read more about relations
@ -302,13 +319,13 @@ async def aggregations():
# exists
assert await Book.objects.filter(title="The Hobbit").exists()
# max
# maximum
assert 1990 == await Book.objects.max(columns=["year"])
# min
# minimum
assert 1937 == await Book.objects.min(columns=["year"])
# avg
# average
assert 1964.75 == await Book.objects.avg(columns=["year"])
# sum
@ -318,6 +335,49 @@ async def aggregations():
# visit: https://collerek.github.io/ormar/queries/aggregations/
async def raw_data():
# extract raw data in a form of dicts or tuples
# note that this skips the validation(!) as models are
# not created from parsed data
# get list of objects as dicts
assert await Book.objects.values() == [
{"id": 1, "author": 1, "title": "The Hobbit", "year": 1937},
{"id": 2, "author": 1, "title": "The Lord of the Rings", "year": 1955},
{"id": 4, "author": 2, "title": "The Witcher", "year": 1990},
{"id": 5, "author": 1, "title": "The Silmarillion", "year": 1977},
]
# get list of objects as tuples
assert await Book.objects.values_list() == [
(1, 1, "The Hobbit", 1937),
(2, 1, "The Lord of the Rings", 1955),
(4, 2, "The Witcher", 1990),
(5, 1, "The Silmarillion", 1977),
]
# filter data - note how you always get a list
assert await Book.objects.filter(title="The Hobbit").values() == [
{"id": 1, "author": 1, "title": "The Hobbit", "year": 1937}
]
# select only wanted fields
assert await Book.objects.filter(title="The Hobbit").values(["id", "title"]) == [
{"id": 1, "title": "The Hobbit"}
]
# if you select only one column you could flatten it with values_list
assert await Book.objects.values_list("title", flatten=True) == [
"The Hobbit",
"The Lord of the Rings",
"The Witcher",
"The Silmarillion",
]
# to read more about extracting raw values
# visit: https://collerek.github.io/ormar/queries/aggregations/
async def with_connect(function):
# note that for any other backend than sqlite you actually need to
# connect to the database to perform db operations
@ -345,6 +405,7 @@ for func in [
subset_of_columns,
pagination,
aggregations,
raw_data,
]:
print(f"Executing: {func.__name__}")
asyncio.run(with_connect(func))