这就是它是如何为我工作的，family_id是自动增量的主键，我使用Laravel7

    public function store(Request $request){
        $family = new Family();
        $family->family_name = $request->get('FamilyName');
        $family->family_no = $request->get('FamilyNo');
        $family->save();
        //family_id is the primary key and auto increment
        return redirect('/family/detail/' .  $family->family_id);
    }

同样在Model Family文件中，应该将增量设置为true，否则上面的$ Family——>family_id将返回空

    public $incrementing = true;
  

在laravel 5中:你可以这样做:

use App\Http\Requests\UserStoreRequest;
class UserController extends Controller {
    private $user;
    public function  __construct( User $user )
    {
        $this->user = $user;
    }
    public function store( UserStoreRequest $request )
    {
       $user= $this->user->create([
            'name'              => $request['name'],
            'email'             => $request['email'],
            'password'          => Hash::make($request['password'])
        ]);
        $lastInsertedId= $user->id;
    }
}

你可以使用$this构造函数变量在当前函数或控制器中实现“使用Laravel Eloquent最后插入Id”(不添加任何额外列)。

public function store(Request $request){
    $request->validate([
        'title' => 'required|max:255',
        'desc' => 'required|max:5000'
    ]);

    $this->project = Project::create([
        'name' => $request->title,
        'description' => $request->desc,
    ]);

    dd($this->project->id);  //This is your current/latest project id
    $request->session()->flash('project_added','Project added successfully.');
    return redirect()->back();

}

您可以很容易地获取最后插入的记录Id

$user = User::create($userData);
$lastId = $user->value('id');

从DB中最后插入的记录中获取Id是一个很棒的技巧。

下面是我们如何在Laravel 4中获得最后一个插入id

public function store()
{
    $input = Input::all();

    $validation = Validator::make($input, user::$rules);

    if ($validation->passes())
    {

     $user= $this->user->create(array(
            'name'              => Input::get('name'),
            'email'             => Input::get('email'),
            'password'          => Hash::make(Input::get('password')),
        ));
        $lastInsertedId= $user->id; //get last inserted record's user id value
        $userId= array('user_id'=>$lastInsertedId); //put this value equal to datatable column name where it will be saved
        $user->update($userId); //update newly created record by storing the value of last inserted id
            return Redirect::route('users.index');
        }
    return Redirect::route('users.create')->withInput()->withErrors($validation)->with('message', 'There were validation errors.');
    }

xdazz在这种情况下是正确的，但为了将来可能使用DB::statement或DB::insert的访问者的利益，还有另一种方法:

DB::getPdo()->lastInsertId();