SQLSTATE [42S22]：未找到列：1054 'where 子句'中的未知列'items.box_box_barcode'

Question

我正在尝试显示来自 2 个数据库表（boxes 和 items）的数据，这些表在 Laravel 5.8 中具有 2 个具有一对多关系的模型。当我尝试在视图中显示数据时，出现以下错误：

SQLSTATE[42S22]：找不到列：1054 'where 子句'中的未知列 'items.box_box_barcode'（SQL：从 `items` 中选择 *，其中 `items`.`box_box_barcode` = TRTB0001 和 `items`。` box_box_barcode` 不为空）

查看我的代码：

Box.php（模型）

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Box extends Model
{

    protected $guarded = [];


    protected $primaryKey = 'box_barcode';
    public $incrementing = false;
    protected $keyType = 'string';



    public function items(){

        return $this->hasMany(Item::class);
    }
}

Item.php（模型）

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Item extends Model
{

    protected $primaryKey = 'item_barcode'; // or null

    public $incrementing = false;

    // In Laravel 6.0+ make sure to also set $keyType
    protected $keyType = 'string';


    public function company(){

        return $this->belongsTo(Company::class);
    }
}

create_boxes_table.php（迁移 1）

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateBoxesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('boxes', function (Blueprint $table) {
            //$table->bigIncrements('id');
            $table->string('box_barcode')->primary();
;      //want this to be my id that can increment
            $table->string('sort_description');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('boxes');
    }
}

create_items_table.php（迁移 2）

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateItemsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('items', function (Blueprint $table) {
            //$table->bigIncrements('id');
            $table->string('item_barcode')->primary();
; //want this to be my id that can increment
            $table->string('its_box_barcode');
            $table->string('item_quality');
            $table->timestamps();


        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('items');
    }
}

boxesController.php（控制器）

<?php

namespace App\Http\Controllers;

use App\Box;
use Illuminate\Http\Request;

class boxesController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $boxes = Box::all();       
        return view('boxes.index', compact('boxes'));
    }


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

    /**
     * Display the specified resource.
     *
     * @param  \App\Box  $box
     * @return \Illuminate\Http\Response
     */
    public function show(Box $box)
    {
        return view('boxes.show', compact('box'));
    }


}

index.blade.php（视图）

@extends('layout')


@section('title', 'Boxes')  


@section('content')


    <h1>Boxes</h1>

     <ul style="list-style-type: none;">

       @foreach($boxes as $box) 

         <li>
            <a href="/boxes/{{ $box->box_barcode }}">
                {{$box->box_barcode}}  
            </a>
         </li>

       @endforeach

    </ul>           

 @endsection

show.blade.php（查看）

@extends('layout')


@section('title', 'Show Box')  


@section('content')


@if ($box->items->count())
    <div>
        @foreach ($box->items as $item)

            <div>

                <form method="POST" action="/items/{{ $item->id }}">
                    @method('PATCH')
                    @csrf

                    <!-- USE TO STRIKETHROUGH A CONPLETED TASK IN WEB PAGE -->
                    <label class="checkbox {{ $item->in ? 'is-complete' : '' }}" for="in" >

                    <input type="checkbox" name="in" onChange="this.form.submit()" {{ $item->in ? 'checked' : '' }}>
                            {{ $item->item_barcode }}

                    </label>


                </form>



            </div>

        @endforeach

    </div>
@endif

@endsection

Answer 1

通过为列使用奇怪的名称，您会失去很多 Laravel 通常自动执行的功能。但正如the documentation 中所述，您可以“通过向 hasMany 方法传递额外的参数来覆盖外键和本地键。”

<?php
namespace App;

use Illuminate\Database\Eloquent\Model;

class Box extends Model {
    protected $guarded = [];
    protected $primaryKey = 'box_barcode';
    public $incrementing = false;
    protected $keyType = 'string';

    public function items() {
        return $this->hasMany(Item::class, 'its_box_barcode', 'box_barcode');
    }
}

您还需要定义项目和盒子之间的反向关系，同样使用您的非标准列名。

<?php
namespace App;

use Illuminate\Database\Eloquent\Model;

class Item extends Model {

    protected $primaryKey = 'item_barcode'; // or null
    public $incrementing = false;
    protected $keyType = 'string';


    public function box() {
        return $this->belongsTo(Box::class, 'its_box_barcode', 'box_barcode');
    }
}

---

建议您坚持使用框架的预期命名约定，这样可以省去很多麻烦。即boxes.box_barcode应该是boxes.barcode，items.item_barcode应该是items.barcode，而items.its_box_barcode应该是items.box_id，指向一个名为id的标准数字键列。是的，如果您已经在数据库中拥有另一个独特的值，这有点浪费，但如果您不这样做，您将违反惯例。所以我建议的模型代码会很简单：

<?php
namespace App;

use Illuminate\Database\Eloquent\Model;

class Box extends Model {
    public function items() {
        return $this->hasMany(Item::class);
    }
}

class Item extends Model {
    public function box() {
        return $this->belongsTo(Box::class);
    }
}

您还应该在迁移中使用 foreign key constraints 在数据库级别定义这些关系：

Schema::create('boxes', function (Blueprint $table) {
    $table->bigIncrements('id')->primary();
    $table->string('barcode');
    $table->string('sort_description');
    $table->timestamps();
});

Schema::create('items', function (Blueprint $table) {
    $table->bigIncrements('id')->primary();
    $table->string('box_id');
    $table->string('barcode');
    $table->string('quality');
    $table->timestamps();
    $table->foreign('box_id')->references('id')->on('boxes')->onDelete('cascade');
});

现在，您可以在模板中引用如下内容：

@foreach ($boxes as $box)
    {{ $box->barcode }} 
    @foreach ($box->items as $item)
        {{ $item->barcode }}
    @endforeach
@endforeach