Back reference filter

[art1415926535]

What need to do for allow query like this

query {
    authors (filters: {book_set__name: "bar1"}){
        edges {
            node {
                id
                name
                book_set {
                    edges {
                        node {
                            id
                            name
                        }
                    }
                }
            }
        }
    }
}

I get the following error

GraphQLLocatedError('missing FROM-clause entry for table "t3"\nLINE 1: ..."t1"."id", "t1"."name" FROM "author" AS t1 WHERE ("t3"."name...\n                                                             ^\n',)

[insolite]

Unfortunately there's no way to filter parent query by subset's fields at the moment. At the same time as for me it's still quite undefined behavior. Here we have several options we might want to achieve (maybe even more):

• authors with at least one book with certain name, selecting only matching books as a subset
• authors with at least one book with certain name, but selecting all books as a subset
• authors with all books matching filters, selecting all books as a subset

However since now subsets are resolved as separate queries, there's an implementation possibility:

query {
    authors {
        edges {
            node {
                id
                name
                book_set (filters: {name: "bar1"}) {
                    edges {
                        node {
                            id
                            name
                        }
                    }
                }
            }
        }
    }
}

Thus we have separated filter for subsets. I've already implemented this so I'll push it soon.

It's still without filtering parent query though. I'm thinking about some kind of subset characteristics lookup like author (book_set__count__gt: 0) but yet, can't figure out how to implement it.

[insolite]

Subset filtering case is ready in b237d49, released to 2.2.0

graphene-peewee-async/tests/test_api/test_query.py

Lines 101 to 122 in b237d49

	query {
	authors {
	count
	total
	edges {
	node {
	id
	name
	book_set (filters: {name: "bar1"}) {
	count
	total
	edges {
	node {
	id
	name
	}
	}
	}
	}
	}
	}
	}

[insolite]

BTW, I nearly accidentally fixed sync queries necessity at subset fetching 😀. So now it's safe to use db.set_allow_sync(False) along with _set fields.

[art1415926535]

I think Django's style will be better

authors with at least one book with certain name, but selecting all books as a subset

This option will cover most different uses with a separate filter for subsets.