如何解决如何在laravel中的表内创建关系?
我需要在表中创建一个关系。我在下面附上了我的桌子。
这是我的类别模型。
class Category extends Model
{
public function products()
{
return $this->hasMany(Product::class);
}
public function categories_id() {
return $this->hasMany('category_id','parent_id');
}
public function parent_id() {
return $this->hasMany('category_id','parent_id');
}
}
在这里如何关联category_id和parent_id?
这是我的 categories_table 。
public function up()
{
Schema::create('categories',function (Blueprint $table)
{
$table->bigIncrements('id');
$table->unsignedBigInteger('parent_id')->nullable();
$table->string('cat_name')->nullable();
$table->string('cat_image_path')->nullable();
$table->timestamps();
});
}
解决方法
您可以尝试以下设置:
public function parent()
{
return $this->belongsTo(self::class);
// uses `parent_id` to find the parent by 'id'
}
public function children()
{
return $this->hasMany(self::class,'parent_id');
// finds other records where their 'parent_id' is the parent's 'id'
}
$category = Category::find(...);
$parent = $category->parent;
$children = $category->children;
此外,您的架构中没有category_id
字段。
关于这些关系的所有信息都在文档中。
Laravel 7.x Docs - Eloquent - Relationships - One To Many hasMany
Laravel 7.x Docs - Eloquent - Relationships - One To Many (Inverse) belongsTo
Laravel 7.x Docs - Eloquent - Relationships - Relationship Methods vs Dynamic Properties