How to filter by counts? about loopback-counts-mixin HOT 2 OPEN

any updates on this? This would be a great feature

from loopback-counts-mixin.

@gijo-varghese @enceladus unfortunately this cannot be done as loopback-counts-mixin only iterates over existing relations (starting with has) and injects virtual field with it, there isn't even a straightforward way of conditional counting as resource[relation].count() does not have any placeholder for an argument.

The easiest way of achieving counting models would be doing this in 2 steps: first adding include filter field which fetches related models (note that they are provided as relations, in lb2 retrievable via getAsync() and in lb3 with .findAll(), and then, for every relation injected with include you have to call .count(filter) method with filter representing your conditions, consider

List all users from Poland having more than 10 books with title containing Tadeusz Chciuk

    const usersFromPoland = app.models.User.find({where: {"email": {like: "%.pl"}}, include: {"books": }}).then(users => Promise.all(users.map(u => u.books.count({where: {"title": {like: "%Tadeusz Chciuk%"}}}).then(books => {return {user: u, count: books.length}}))).then(usersWithBooks => userWithBooks.filter(uwb => uwb.count > 10))

assuming that there's another model Book and there's relation User<->Book

Another way could be introducing this plugin to relations interface or even Inclusion interface.

Have fun!

from loopback-counts-mixin.