Laravel 属于多返空

Question

我在返回属于许多关系时遇到问题。这是我的场景。我有“Individual”模型和“Group”模型，其中每个个人可以属于多个组，每个组可以属于多个用户。使用诸如“localhost/phpmyadmin”之类的数据库蓝图很好，因为我可以单击“group_individual”表上的“组”列，它会返回到“组”表上的相关组。但是在 Laravel 中工作，我得到的是空数组。你能帮我吗？感谢您的宝贵时间。

迁移

Schema::create('groups', function (Blueprint $table) {
    $table->id();
    $table->string('group_id')->unique();
    $table->string('name');
    $table->unsignedBigInteger('members');
    $table->string('url')->nullable();
    $table->timestamps();
});

Schema::create('individuals', function (Blueprint $table) {
    $table->id();
    $table->string('search_id')->unique();
    $table->timestamps();
});

Schema::create('group_individual',function($table){
    $table->id();
    $table->string('group');
    $table->string('individual');
    $table->foreign('group')->references('group_id')->on('groups')->onDelete('cascade');
    $table->string('type');
    $table->foreign('individual')->references('search_id')->on('individuals')->onDelete('cascade');
});

个体模型

public function groups():\Illuminate\Database\Eloquent\Relations\BelongsToMany
{
    return $this->belongsToMany(Group::class,'group_individual','individual','group');
}

组模型

public function individuals():\Illuminate\Database\Eloquent\Relations\BelongsToMany
{
    return $this->belongsToMany(Individual::class,'group_individual','group','individual');
}

控制器

public function import(){
    Individual::create([]);
    Group::create([]);
    \DB::table('group_individual')->insert(['group'=>,'individual'=>,'type'=>]);
    $individual=Individual::find(1);
    dd($individual->groups);
}

来自上述控制器的$individual->groups 返回空数组。

Answer 1

我找到了解决方案。我尝试使用两个表的 id 而不是自定义其他属性。 这是我使用的代码。我没有使用 DB::insert() 方法，而是使用 attach 方法。

迁移

Schema::create('groups', function (Blueprint $table) {
            $table->id();
            $table->string('group_id')->unique();
            $table->string('name');
            $table->unsignedBigInteger('members');
            $table->string('url')->nullable();
            $table->timestamps();
        });
     
    Schema::create('individuals', function (Blueprint $table) {
                $table->id();
                $table->string('search_id')->unique();
                $table->timestamps();
            });
    Schema::create('group_individual',function($table){
               $table->foreignId('group_id')->constrained()->onDelete('cascade');
               $table->foreignId('individual_id')->constrained()->onDelete('cascade');
               $table->string('type');
            });

个人模特

public function groups(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
    {
        return $this->belongsToMany(Group::class,'group_individual','individual_id','group_id');
    }

组模型

public function individuals(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
    {
        return $this->belongsToMany(Individual::class,'group_individual','group_id','individual_id');
    }

控制器

$a=Individual::create();
$b=Group::create();
$a->groups()->attach($b->id);

Answer 2

看起来你已经反转了 ID 键，尝试在 belongsToMany 方法中切换“组”和“个人”