Yii2 hasMany custom condition - php

Question

I have sql condidtion SELECT * FROM (SELECT * FROM Prices WHERE aliasId = :aliasId order by id desc) p1 group by p1.currency and I am trying to use it in hasMany statement.
$q = $this->hasMany(Prices::className(), ['aliasId' => 'id']);
$db = \Yii::$app->db;
$query = $db
->createCommand('SELECT * FROM (SELECT * FROM Prices WHERE aliasId = :aliasId order by id desc) p1 group by p1.currency')
->bindValue(':aliasId', $this->id);
$query->prepare(true);
$q->sql = $query->getRawSql();
return $q;
But $this->id is empty when hasMany calling. Is there any way to bind custom query and link array there?
UPDATE.
I know that the reason of $this->id is empty, because I'm using Prices::find()>with('prices') in my Controller, so Yii creates query for all prices list. hasMany just adds addWhere('in', $key, $value) in empty query from $link parameter, I'm trying to override his query, but I can't.

Answer 1

$this->id is empty for new PriceAlias instances, and it's filled only after the model is saved in db - you are getting an empty value most likely because getPrices() is called before the model is saved in db.
You can test if $this->id != null or $this->isNewRecord == false before building the custom command, otherwise return null, an empty array or as required.
UPDATE 1: not sure I fully understand your update,
Prices::find()>with('prices') does create a WHERE ... IN (...) query, but
hasMany does not add an addWhere rule, it creates a relation for the ActiveRecord class. In your case:
$this->hasMany(Prices::className(), ['aliasId' => 'id'])
// generates: SELECT * FROM `prices` WHERE `aliasId` = :id
And the query is executed only when you specifically call getPrices() for an object.
So your problem is? after $q->sql = $query->getRawSql(); statement, $q->sql is not SELECT * FROM (SELECT * FROM Prices WHERE aliasId = :aliasId order by id desc) p1 group by p1.currency ?
UPDATE 2: I understand now. I can't think of any way of using Prices::find()->with() on relations with custom sql, at least not as the one you would like to use.
I can only suggest to find an alternative to find()->with() in your controller if you need to keep the custom query.

Answer 2

From official doc:
$subQuery = (new Query())->select('id')->from('user')->where('status=1');
// SELECT * FROM (SELECT `id` FROM `user` WHERE status=1) u
$query->from(['u' => $subQuery]);
In your case it should be something like this:
$subQuery = (new Query())->select('*')->from('Prices')->where('aliasId = :aliasId', ['aliasId'=>$aliasId])->orderBy('id');
$query->from(['p1' => $subQuery])->groupBy('p1.currency');