Ошибка SQL при попытке создать фильтр

Integrity constraint violation: 1052 Column 'category_id' in where clause is ambiguous The SQL being executed was: SELECT COUNT(*) FROM product p LEFT JOIN category ON p.category_id = category.id LEFT JOIN product ON category.id = product.category_id WHERE (p.category_id='1') AND (category_id IN ('1', '6', '7', '8'))

Пытаюсь вывести продукты из дочерних категорий при выборе родительской.

ProductSearch:

    public function search($params)
{
    $query = Product::find()
        ->from(['p' => Product::tableName()])
        ->with(['designer', 'category'])
        ->joinWith([
            'childrenProducts pp' => function (ActiveQuery $query) {
                if (!empty($this->category_id)) {
                    $ids = [$this->category_id];
                    $childrenIds = $ids;
                    while ($childrenIds = Category::find()
                        ->select('id')
                        ->andWhere(['parent_id' => $childrenIds])
                        ->column()) {
                            $ids = array_merge($ids, $childrenIds);
                        }
                    $query->andWhere(['category_id' => array_unique($ids)]);
                }
            }
        ]);
    // add conditions that should always apply here
    $dataProvider = new ActiveDataProvider([
        'query' => $query,
    ]);
    $this->load($params);
    if (!$this->validate()) {
        // uncomment the following line if you do not want to return any records when validation fails
        // $query->where('0=1');
        return $dataProvider;
    }
    // grid filtering conditions
    $query->andFilterWhere([
        'p.id' => $this->id,
        'p.category_id' => $this->category_id,
        'p.designer_id' => $this->designer_id,
        'p.price' => $this->price,
        'p.new' => $this->new,
        'p.hit' => $this->hit,
        'p.sale' => $this->sale,
        'p.created_at' => $this->created_at,
        'p.updated_at' => $this->updated_at,
        'pp.childrenProducts' => $this->childrenProducts
    ]);

Product:

/**
 * @return \yii\db\ActiveQuery
 */
public function getCategory()
{
    return $this->hasOne(Category::className(), ['id' => 'category_id']);
}
/**
 * @return \yii\db\ActiveQuery
 */
public function getDesigner()
{
    return $this->hasOne(Designer::className(), ['id' => 'designer_id']);
}
public function getChildrenProducts()
{
    return $this->hasMany(Product::className(), ['category_id' => 'id'])->indexBy('id');
}

Давно пытаюсь подружить, но... только учусь и не понимаю всей магии. Пожалуйста объясните подробно. Может быть есть другие варианты для этой задачи?