Translate SQL query to CakePHP 3.0 - mysql

Question

The query is as follows
select T.username,
sum(T.size) as totSize,
count(*) total,
count(case when T.type = 'facebook' then 1 else null end) as facebook,
count(case when T.type = 'instagram' then 1 else null end) as instagram,
count(case when T.type = 'device' then 1 else null end) as device
from (SELECT users.username, pictures.size, pictures.type from users left join pictures on pictures.user_id = users.id) as T
group by T.username
Associated to each 'user' there are several 'picture'.
Basically, what I want to do is:
Left join users and pictures table
count pictures by their type
sum up picture sizes
group by user
The SQL query works when applied to the database, but I need to represent this within my CakePHP 3.0 application.
I managed to LEFT JOIN tables using model associations. In UsersTable:
$this->hasMany('Pictures', [
'foreignKey' => 'user_id',
'joinType' => 'LEFT'
]);
Then in my find method:
$options['contain'] = ['Pictures' => function ($q) {
return $q
->select(['user_id', 'size', 'type']);}];
$options['fields'] = array('Users.username');
$query = $this->find('all', $options);
How to continue the query? If I try to access to contained data (as with 'Pictures.type') I'm returned with SQL error stating that the column isn't in the field list.
I feel this might be the wrong approach, but I can't think of other ways.
Thanks in advance!

Answer 1

solved
$options['contain'] = array('Users');
$query = $this->Pictures->find('all', $options);
$query->select(['Users.username', 'Users.plan', 'Users.id']);
$query->select(['sum' => $query->func()->sum('size'),])
->select(['count' => $query->func()->count('*'),])
->select(['facebook' => $query->func()
->count('case when type = \'facebook\' then 1 else null end'),])
->select(['instagram' => $query->func()
->count('case when type = \'instagram\' then 1 else null end'),])
->select(['device' => $query->func()
->count('case when type = \'device\' then 1 else null end'),])
->group('user_id');
return $query;
This allows to select joined fields as
$result = $query->all();
$result->user->username;