Laravel 5 关系有一个保存（）？

Question

我有两个表 Projects 和 Galleries。项目有一个画廊。在画廊表中，我有一个外键 project_id。

Schema::table('galleries', function (Blueprint $table) {

            $table->integer("project_id")->unsigned()->nullable()->default(null);

            $table->foreign("project_id")
                    ->references("id")
                    ->on("projects")
                    ->onDelete("set null");

        });

在项目模型中，我有一个函数可以获取与项目关联的图库：

public function gallery()
  {
    return $this->hasOne("App\Gallery");
  }

创建新项目时，用户从图库下拉列表中选择，然后在保存新项目时，如何更新图库表以使用新创建的 projects_id

$gallery_id = 2; // user selected gallery 2

$project = new Project();
$project->title = "new project";
$project->save(); 

Answer 1

尝试以下方法：

$gallery_id = 2; // user selected gallery 2

$project = new Project();
$project->title = "new project";
$project->save(); 

$gallery = Gallery::find($gallery_id);
$gallery->project_id = $project->id;
$gallery->save();