填充多对多关系有问题，查询找不到我的category_id列

Question

使用 laravel v9 和 Filament v2 对于我的多对多关系 书籍和类别

这是错误

SQLSTATE[HY000]: General error: 1364 Field 'category_id' doesn't have a default value
INSERT INTO
  `books` (
    `image`,
    `title`,
    `author_id`,
    `publication_date`,
    `copies`,
    `updated_at`,
    `created_at`
  )
VALUES
  (
    Uqvz9qyKeqt11XmrlntLZuWWkgKYjT - metaNDAzNjI1ODg3XzE4MDU4MDc2MTY1MzUyNjdfOTIxNjYxODQ2MjE5MTc5ODE1OV9uLmpwZw = = -.jpg,
    AS,
    1,
    AS,
    AS,
    2023 -12 -13 16: 14: 00,
    2023 -12 -13 16: 14: 00
  ) 

“as”是我测试它的输入

我的填写表格

public static function form(Form $form): Form
    {
    return $form
        ->schema([
            Card::make()
            ->schema([
                FileUpload::make('image')->image(),
                TextInput::make('title')
                ->required()
                ->maxLength(255),
                select::make('author_id')   
                ->relationship('author', 'full_name')
                ->required(),
                Select::make('category_id')
                ->multiple()    
                ->relationship('categories', 'name')
                ->preload()
                ->required(),
                TextInput::make('publication_date')
                ->required()
                ->maxLength(255),
                TextInput::make('copies')
                ->required()
                ->maxLength(255)
            ])
        ]);
    }

对于我的模型

class Book extends Model
    {
        use HasFactory;

        protected $fillable = ['author_id','image','category_id','title','language','publication_date','copies']; 

        protected $casts = [
            'category_id' => 'array',
        ];

        public function author(){
            return $this->belongsTo(Author::class);
        } 

        public function categories(){
            return $this->belongsToMany(Category::class);
        }  
    }    `

`class Category extends Model
{
    use HasFactory;

    protected $fillable = ['name']; 
        
    public function books(){
        return $this->hasMany(Book::class);
    }  
}  

为了我的迁移

  public function up()
    {
        Schema::create('books', function (Blueprint $table) {
            $table->id();
            $table->foreignId('author_id')->constrained()->cascadeOnDelete();
            $table->foreignId('category_id')->constrained()->cascadeOnDelete();
            $table->string('image'); 
            $table->string('title'); 
            $table->string('publication_date');
            $table->string('copies');    
            $table->timestamps();
        });
    } 

 public function up()
    {
        Schema::create('categories', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->timestamps();
        });
    } 

我尝试了很多方法，但似乎无法解决 我希望它作为数组保存到我的数据库中，因为它是多对多的关系 这样我就可以在灯丝表中显示它

Answer 1

根据您的桌子设计，这是行不通的。

您已添加

belongsToMany

关系。 不过，应该是这样的

模型\Book.php

class Book extends Model
{
    public function category()
    {
        return $this->belongsTo(Category::class);
    }
}

模型\Category.php

class Category extends Model
{
    public function books()
    {
        return $this->hasMany(Book::class);
    }
}

在这种情况下，您一次只能为预订分配一个类别。

如果您想为一本书分配多个类别，请创建一个数据透视表

book_category

并且在关系中您需要添加以下更改

模型\Book.php

class Book extends Model
{
    public function categories()
    {
        return $this->belongsToMany(Category::class);
    }
}

模型\Category.php

class Category extends Model
{
    public function books()
    {
        return $this->belongsToMany(Book::class);
    }
}

然后在您的选择输入中将使用此

Select::make('category_id')
   ->multiple()    
   ->relationship('categories', 'name')
   ->preload()
   ->required(),

更多参考，

V2：https://filamentphp.com/docs/2.x/forms/fields#populate-automatically-from-a-relationship

V3：https://filamentphp.com/docs/3.x/forms/fields/select#integrating-with-an-eloquent-relationship