使用propel从OneToOne关系中获取JSON

I'm going to get a JSON like following structure from my database:

{
"Users": [
    {
        "Id": 1,
        "Name": "a",
        "Family": "b",
        "RegisterId": 1,
        "AccessType": 1,
        "Username": "abc"
    },
    {
        "Id": 2,
        "Name": "x",
        "Family": "y",
        "RegisterId": 2,
        "AccessType": 1,
        "Username": "xyz"
    }
]
}

Id,Name,Family,RegisterId,AccessType are User_TBL columns and Username is Register_TBL column.

I can get this JSON using below query:

SELECT u.id,u.name,u.family,u.access_type,u.register_id,r.username
FROM `user` as u LEFT JOIN `register` as r 
ON u.register_id = r.id

I'm trying to use below line using propel, but it just shows all User_TBL columns.

$userList = UserQuery::create()-> joinWith('User.Register')-> find();

What's your suggestion ?!

I used below code and it solved my problem.

$userList = UserQuery::create()
        -> leftJoinRegister()
        -> select(array('ID','NAME','FAMILY','AccessType'))
        -> withColumn('Register.Username' , 'Username')
        ->find();