Question: I'm using Sails.js version `0.10.0-rc4`. All models are using sails-mysql.

I'm trying to query a model which has an "one-to-many" association to another model (the query is happening on the "many" side).

It looks something like this:

```
Post.find()
    .where({ category: category_id })
    .populate("category")
    .exec( ... )

```

This gives me an empty array back however when I leave out the `.populate("category")` I get the correct result set.

I know that I could leave `.populate("category")` out and then fetch each correlating Category object separately, but I'm wondering if there's a better solution to this problem.

Answer: 
It's not 100% clear what you're trying to do here. If your goal is to filter the categories that get populated on the `Post`, you can do:

```
Post.find()
    .populate("category", {where: { category: category_id }})
    .exec( ... )

```

If you want to only retrieve `Post`s with a certain category, you would do:

```
Category.findOne(category_id)
        .populate("posts")
        .exec(function(e, c) {console.log(c.posts);})

```
*Original post was too soon*

Following works for me (sails 0.12) with population:

```
Post.find({category: category_id})
    .populate("category")
    .exec( ... )

```

But I am still puzzled who to search in a subquery any other attribute than id..

Edit2: Seems like deep query is not yet supported: <https://github.com/balderdashy/waterline/issues/266>