php – Laravel Sync错误

if( $organisation->save() ) {

        if(isset($members)) {
            $organisation->users()->sync($members);
        }

        if(isset($teams)) {
            $organisation->teams()->sync($teams);
        }

        if(isset($teams)) {
            $organisation->clients()->sync($clients);
        }

        if(isset($projects)) {
            $organisation->projects()->sync($projects);
        }

        $organisation->load('users');
        $organisation->load('teams');
        $organisation->load('clients');
        $organisation->load('projects');

        return Response::make($organisation,200);

    }

当我尝试同步$projects时,我收到以下错误,

数组看起来像这样,

[0] => 6所以一个非常非常简单的数组.我在模型中的关系看起来像这样,

组织

public function projects()
{
    return $this->hasMany('Project');
}

项目

public function organisations()
{
    return $this->belongsToMany('Organisation','organisation_id');
}

正如您所看到的,我组织可以拥有许多项目.我看不出有什么原因会导致以下错误,

Call to undefined method IlluminateDatabaseQueryBuilder::sync()