paulzi / yii2-nested-intervals

    /**

     * @return \yii\db\ActiveQuery

     */

    public function getPrev()

    {

        $tableName = $this->owner->tableName();

        $query = $this->owner->find()

            ->andWhere([

                'and',

                ['<', "{$tableName}.[[{$this->rightAttribute}]]", $this->owner->getAttribute($this->leftAttribute)],

                ['>', "{$tableName}.[[{$this->rightAttribute}]]", $this->getParent()->select([$this->leftAttribute])],

            ])

            ->andWhere($this->treeCondition())

            ->orderBy(["{$tableName}.[[{$this->rightAttribute}]]" => SORT_DESC])

            ->limit(1);

        $query->multiple = false;

        return $query;

    }

    /**

     * @return \yii\db\ActiveQuery

    /**

     * @return \yii\db\ActiveQuery

     */

    public function getNext()

    {

        $tableName = $this->owner->tableName();

        $query = $this->owner->find()

            ->andWhere([

                'and',

                ['>', "{$tableName}.[[{$this->leftAttribute}]]", $this->owner->getAttribute($this->rightAttribute)],

                ['<', "{$tableName}.[[{$this->leftAttribute}]]", $this->getParent()->select([$this->rightAttribute])],

            ])

            ->andWhere($this->treeCondition())

            ->orderBy(["{$tableName}.[[{$this->leftAttribute}]]" => SORT_ASC])

            ->limit(1);

        $query->multiple = false;

        return $query;

    }

    /**

     * Populate children relations for self and all descendants