src/Models/Tree.php
public function getNode($id, $columns = ['*'])
	{
		$columns = $this->formatColumns($columns);
		return empty($id) ? (new static)->newFromBuilder([
				$this->getKeyName() => 0,
				$this->parentKey => NULL,
				$this->pathKey => '/0/',
				$this->orderKey => 0,
				$this->levelKey => 0,
			]) : static::find($id, $columns);
	}
public function getNode($id, $columns = ['*'])
	{
		$columns = $this->formatColumns($columns);
		return empty($id) ? (new static)->newFromBuilder([
				$this->getKeyName() => 0,
				$this->parentKey => NULL,
				$this->pathKey => '/0/',
				$this->orderKey => 0,
				$this->levelKey => 0,
			]) : static::find($id, $columns);
	}
获取指定ID的Node

@param  integer $cid 输入ID
@return mixed      输出查询结果