Array query operators

[art049]

Suggested implementation of $elemMatch $all and $size

MongoDB Reference

Example model:

class Thing(Model):
    array: List[int]

$elemMatch

Array containing the number 42 at least once:

Thing.array.any().eq(42)
eq(Thing.array.any(), 42)
Thing.array.any() == 42
42 in Thing.array # if possible using __contains__

$elemMatch

Array containing only elements greater than 12:

Thing.array.all().gt(42)
gt(Thing.array.all(), 42)
Thing.array.all() > 42

$size

Array containing more than 3 elements:

Thing.array.size().gte(3)
gte(Thing.array.size(), 3)
Thing.array.size() >= 3
len(Thing.array) >= 3 # if possible

[erny]

When will be the next release? I would love to have this feature.

But I really need sequences over EmbeddedModels, and I don't know if I should open a new issue (or there is already one) e.g.:

class EmbeddedAuthor(EmbeddedModel):
    name: str
    year: int

class Book(Model):
    title: str
    authors: List[EmbeddedAuthor]

The query could be something like:

Book.authors.any(EmbeddedAuthor.name == "Frederick Forsyth")

but I would love much more:

Book.authors.any().name == "Frederick Forsyth"

Looking about what MongoDB allows to do, it seems that we can query over arrays with the "any" operator transparently, i.e.:

Thing.array.any() == 42

and

Thing.array == 42

would be the same. This is especially interesting for embedded models:

Book.authors.name == "Frederick Forsyth"

which should read like "Tell me which books have at least one author with name "Frederick Forsyth".

Thanks again for this great piece of software.

[art049]

Hey @erny. Thanks for your enthusiasm :smile: . I'm currently working on this feature, release should come soon :wink:

I totally agree with the use case you described and it should definitely possible to have it with this feature !