Bookshelf JS Relation - Getting Count - node.js

Question

I'm trying to get users count belongs to specific company.
Here is my model;
var Company = Bookshelf.Model.extend({
tableName: 'companies',
users: function () {
return this.hasMany(User.Model, "company_id");
},
users_count : function(){
return new User.Model().query(function(qb){
qb.where("company_id",9);
qb.count();
}).fetch();
},
organization: function () {
return this.belongsTo(Organization.Model, "organization_id");
}
});
method "users" works very well, no problem.
method "users_count" query works well, but cant get value to "company" model.
in routes, i'm using bookshelf models like this;
new Company.Model({id:req.params.id})
.fetch({withRelated:['users']})
.then(function(model){
res.send(model.toJSON())
})
.catch(function(error){
res.send(error);
});
How should i use users_count method, i'm kinda confused (probably because of promises)

Answer 1

Collection#count()
If you upgrade to 0.8.2 you can use the new Collection#count method.
Company.forge({id: req.params.id}).users().count().then(userCount =>
res.send('company has ' + userCount + ' users!');
);
Problem with your example
The problem with your users_count method is that it tries to make Bookshelf turn the result of your query into Models.
users_count : function(){
return new User.Model().query(function(qb){
qb.where("company_id",9);
qb.count();
}).fetch(); // Fetch wanted an array of `user` records.
},
This should work in this instance.
users_count : function(){
return new User.Model().query()
.where("company_id",9)
.count()
},
See relevant discussion here.
EDIT: How to get this in your attributes.
Maybe try something like this:
knex = bookshelf.knex;
var Company = bookshelf.Model.extend({
tableName: 'companies',
initialize: function() {
this.on('fetching', function(model, attributes, options) {
var userCountWrapped = knex.raw(this.getUsersCountQuery()).wrap('(', ') as user_count');
options.query.select('*', userCountWrapped);
}
}
users: function () {
return this.hasMany(User.Model, "company_id");
},
getUsersCountQuery: function() {
return User.Model.query()
.where("company_id",9)
.count();
}
organization: function () {
return this.belongsTo(Organization.Model, "organization_id");
}
});

Answer 2

Check out the bookshelf-eloquent extension. The withCount() function is probably what you are looking for. Your code would look something like this:
let company = await Company.where('id', req.params.id)
.withCount('users').first();

Answer 3

User.collection().query(function (qb) {
qb.join('courses', 'users.id', 'courses.user_id');
qb.groupBy('users.id');
qb.select("users.*");
qb.count('* as course_count');
qb.orderBy("course_count", "desc");
})