laravel中的更新方法将在数据库中创建新模型

Question

我在laravel RESTful API构建中遇到问题，

我有以下控制器

 <?php
 namespace App\Http\Controllers\Kittrans;
 use App\Http\Controllers\Controller;
 use App\Inventory;
 use App\Kittrans;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\DB;

 class KittransController extends Controller
 {

 public function index()
 {

 }
/**
 * Show the form for creating a new resource.
 *
 * @return \Illuminate\Http\Response
 */
public function create()
{
    //
}

/**
 * Store a newly created resource in storage.
 *
 * @param  \Illuminate\Http\Request  $request
 * @return \Illuminate\Http\Response
 */
public function store(Request $request)
{

     $rules =[
    'kmo_id' => 'required',
    'item_id' => 'required|integer|min:1',
    'store_id' => 'required|integer|min:1',
    'count' => 'required|integer|min:1'
    ];

    $this->validate($request,$rules);

    // check if requested count of item less than or equal to count in store
    $inventory = DB::table('inventories')->where(
        [
        ['item_id','=',$request->input('item_id')],
        ['store_id','=',$request->input('store_id')]
        ]
        )->get();

    if($inventory->count()!=1)
    {
         return response()->json(['Error'=>'Model not found'],404);
    }

    $remaining = $inventory->get(0)->count;

    if($request->input('count') > $remaining)
    {
        return response()->json(['Error'=>'Request item count should be less than in the selected store!'],422);
    }


    // get user id bu auth. but for now i will make it static to complete first version of api 
    testing
    $request['user_id'] = 1;
    $newModel = Kittrans::create($request->all());

    $remaining = $remaining - $request->input('count');
    Inventory::where('id',$inventory->get(0)->id)->update(array('count' => $remaining));

    return response()->json($newModel,200);

}

/**
 * Display the specified resource.
 *
 * @param  int  $id
 * @return \Illuminate\Http\Response
 */
public function show(Kittrans $kittrans)
{
    //
    return response()->json($kittrans,200);
}

/**
 * Show the form for editing the specified resource.
 *
 * @param  int  $id
 * @return \Illuminate\Http\Response
 */
public function edit($id)
{
    //
}

/**
 * Update the specified resource in storage.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  int  $id
 * @return \Illuminate\Http\Response
 */
public function update(Request $request, Kittrans $kittrans)
{

    $kittrans->fill($request->only([
        'item_id',
        'kmo_id',
        'count'
        ]));

    if($kittrans->isClean())
    {
        return response()->json(['Error'=>'You should make some changes in your values to update'],422);
    }

    $kittrans->save();
    return response()->json($kittrans,200);
}

/**
 * Remove the specified resource from storage.
 *
 * @param  int  $id
 * @return \Illuminate\Http\Response
 */
public function destroy(Kittrans $kittrans)
{
    //

 $kittrans->delete();

 return response()->json($kittrans,200);
}
}

和route / api.php如下：

Route::resource('kittrans','Kittrans\KittransController',['except'=>['index']]);

当我请求更新数据库中的对象时，问题是将使用$ kittrans-> save（）方法将新模型插入表中！

为什么会发生此问题？

我的邮递员请求看起来像这样：

URL：myApp.test / kittrans / 5003

方法：放置，修补

内容类型：应用程序/ x-www-form-urlencoded

数据：item_id，kmo_id，计数

还我添加了在save（）方法之前，dd($kittrans);和我得到以下内容：

Kittrans {#345
#fillable: array:4 [
0 => "count"
1 => "kmo_id"
2 => "item_id"
3 => "user_id"
]
#connection: null
#table: null
#primaryKey: "id"
#keyType: "int"
+incrementing: true
#with: []
#withCount: []
#perPage: 15
+exists: false
+wasRecentlyCreated: false
#attributes: array:3 [
"item_id" => "1"
"kmo_id" => "1"
"count" => "7"
]
#original: []
#changes: []
#casts: []
#dates: []
#dateFormat: null
#appends: []
#dispatchesEvents: []
#observables: []
#relations: []
#touches: []
+timestamps: true
#hidden: []
#visible: []
#guarded: array:1 [
0 => "*"
]
}

为什么save方法将在db中创建模型的新实例？我在所有其他控制器中都实现了更新方法，一切正常，但是对于此控制器，我不知道问题出在哪里？

Answer 1

没有正确命名用于模型绑定的控制器方法的参数。

您的路线参数是kittran而不是kittrans；资源路由将使用资源的唯一名称作为route参数。您必须为绑定匹配该名称：

public function update(Request $request, Kittrans $kittran)

没有该匹配项，您只是注入一个新的模型实例，而不是发生模型绑定。

您可以运行route:list命令来查看路由的定义方式：

php artisan route:list

“ Laravel自动解析在路由或控制器操作中定义的口才模型，这些操作的类型提示变量名称与路由段名称匹配。” -Laravel 6.x Docs - Routing - Route Model Bindings - Implicit Binding

“默认情况下，Route::resource将基于资源名称的”单数“版本为您的资源路由创建路由参数。” -Laravel 6.x Docs - Controllers - Resource Controllers - Naming Resource Route Parameters

Answer 2

我相信您的模型绑定不正确，当您的模型绑定错误时，Kittrans对象将为空并且不会保存到db，当您填充并保存它时将保存一个新对象。要解决错误的模型绑定，请将其添加到RouteServiceProvider.php。

use App\Kittrans;

public function boot()
{
    parent::boot();

    Route::model('kittrans', Kittrans::class);
}