How to query and convert data to struct with foreign keys as inner struct?

[kyleerhabor]

I'm developing a web API and using this library to make structured queries and responses.

I have a users table defined as so:

  CREATE TABLE users (
    id uuid DEFAULT gen_random_uuid() NOT NULL
        CONSTRAINT users_pkey
            PRIMARY KEY,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP NOT NULL,
    modified_at TIMESTAMP WITH TIME ZONE,
    username TEXT NOT NULL,
    nickname TEXT,
    biography TEXT,
    avatar_id uuid
        CONSTRAINT users_images_id_fkey
            REFERENCES images
);

CREATE UNIQUE INDEX users_username_uindex
    ON users (username);

For the avatar_id column, the images table is defined as so:

CREATE TABLE images (
    id uuid DEFAULT gen_random_uuid() NOT NULL
        CONSTRAINT images_pkey
            PRIMARY KEY,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP NOT NULL,
    modified_at TIMESTAMP WITH TIME ZONE
);

In my source code, I'd use the query_file_as! macro to return an instance of my User struct conforming to the users table structure. The issue I want to address is with the avatar_id column.

Instead of returning the image ID, I'd like to return my Image struct. This would allow the user to request the user and have the avatar image data rather than making a subsequent request for the image data. Is there a way to implement this? If I were to write an SQL query, I could use an INNER JOIN.