How to filter an Association?

[peruzzo]

I want to be able to filter a association, as in the example below only bring the emails assets of a particular user.

var User =  db.define('user', ...);
var Email = db.define('email', ...);
Email.hasOne('user', User, {required: true, reverse: 'emails'});


user.getEmails().find({active: true}).run(...);
user.getEmails().where("active = ?", [true]).all(...);

[dresende]

If you are using hasOne, you only get one association, no reason to filter. If you're using hasMany you can do exactly what you're proposing in your examples.

[peruzzo]

My intention is actually the reverse filter I set the hasOne, I thought the reverse applied a hasMany the user for email.

You said I was supposed to use the hasMany, but I can use without having a join table?

[dresende]

I have to think how to change the interface to allow a reverse hasOne to be a hasMany. There's currently no support for it, but this is on the top of my list.

[taoyuan]

Maybe the phenomenon described in #281 has the same reason. The hasOne and hasMany make me confused. I'm looking forward that this problem is resolved.

[starwing]

and #237 as well.

Maybe it's very easy one: in interface, just makes reversed getAccessor return a ChainFind, so we can filter/count/limit, etc. on it.

in theory, a hasOne is a 1-to-n relation, a table A has a B_id, it means table B may have many different A instance. so at the reversed case, it should be a n-to-1 relation.

hopes to see this is implement :-)

[dresende]

@starwing is right, a reversed hasOne should behave very similar to a normal hasMany. I'm hoping to fix this until the end of next week. Hopefully I'll also add more detail in the wiki about the differences in associations.

[Fauntleroy]

@dresende I've started to run into this issue in a variety of places. Has there been any progress on this?

[dresende]

It depends on the place. Do you have examples?

[Fauntleroy]

We have models User and Like. We have this association:

Like.hasOne( 'owner', User, {
    reverse: 'likes'
});

I think I should be able to use:

User.get( 1, function( err, user ){
    user.getLikes().limit(5).run( function( err, likes ){
        console.log( likes );
    });
});

But I can't since the limit method doesn't exist there.

[dresende]

Please try this latest commit.