Laravel 保存多对多关系

Question

型号

public function categories()
{
    return $this->belongsToMany('App\Category', 'post_categories');
}

public function posts()
{
    return $this->belongsToMany('App\Post', 'post_categories');
}

控制器

public $DEFAULT_LANGUAGE = 1;
public function store(Request $request)
{
    $titles = $request->PostTitle;
    $post = new Post();
    $post->PostTitle = $titles[$this->DEFAULT_LANGUAGE];
    $post->save();
    $post->categories()->attach($request->categoryID[$this->DEFAULT_LANGUAGE]);
    unset($titles[$this->DEFAULT_LANGUAGE]);
    foreach ($titles as $key => $title) {
        $post = new Post();
        $post->PostTitle = $request->PostTitle[$key];
        $post->save();
        $post->categories()->attach($request->categoryID[$key]);
    }

    return response()->json($post);

查看

<select class="form-control category-list" name="categoryID[]" multiple="multiple" data-placeholder="Pilih Kategori">
    @foreach($categories as $category)
        <option value="{{ $category->id }}">
            {{ $category->CategoryName }}
        </option>
    @endforeach
</select>

如果我有两个类别并且我想 select 所有类别，为什么我只得到最后一个类别？我也尝试使用 foreach，但我得到了错误偏移量。任何的想法？

我有两个选项卡窗格.. 我在选项卡 1 中存储两个 categoryID，在选项卡 2 中存储一个 categoryID。然后我单击提交按钮。header 在选项卡 1 中响应两个 categoryID，但在我的数据库中，我只得到最后一条记录

文章标题[1]:sadasd
类别ID[1]:1
类别ID[1]:2
文章标题[2]:asdasd
类别ID[2]:1

控制台显示两个CategoryID..

https://i.stack.imgur.com/jBl2B.png

Answer 1

你用这个模型做什么，它叫什么名字？通常它是这样做的： App\Category:

public function posts()
{
    return $this->belongsToMany('App\Post', 'post_categories');
}

App\Post:

public function categories()
{
    return $this->belongsToMany('App\Category', 'post_categories');
}

这两个关系不在同一个文件中，而是在连接的两个独立模型中。

Answer 2

兄弟，试试这个。我只是在控制器中更改您的代码。希望对您有所帮助:)

型号

public function categories()
{
    return $this->BelongsToMany('App\Category', 'post_categories');
}

public function posts()
{
    return $this->BelongsToMany('App\Post', 'post_categories');
}

控制器

$post = App\Post::findOrFail($id);
$post = $post->load('categories');
$attributes = $post->attributes->toArray();

查看

<select class="form-control category-list" name="categoryID[]" multiple="multiple" data-placeholder="Pilih Kategori">
    @foreach($categories as $category)
        <option value="{{ $category->id }}">
            {{ $category->CategoryName }}
        </option>
    @endforeach
</select>

Answer 3

在您看来，尝试将 multiple="multiple" 更改为 multiple

Answer 4

附加/分离

来自docs

Eloquent also provides a few additional helper methods to make working with related models more convenient. For example, let's imagine a user can have many roles and a role can have many users. To attach a role to a user by inserting a record in the intermediate table that joins the models, use the attach method:

您在附加中仅传递一个值，因此仅获取最后一条记录，以便获得传递所有类别 ID 所需的一切

public $DEFAULT_LANGUAGE = 1;
public function store(Request $request)
{
    $titles = $request->PostTitle;
    $post = new Post();
    $post->PostTitle = $titles[$this->DEFAULT_LANGUAGE];
    $post->save();
    $post->categories()->attach($request->categoryID[$this->DEFAULT_LANGUAGE]);
    unset($titles[$this->DEFAULT_LANGUAGE]);
    $data= array();
    foreach ($titles as $key => $title) {
        $post = new Post();
        $post->PostTitle = $request->PostTitle[$key];
        $post->save();
        $data[]= $post->categories()->attach($request->categoryID[$key]);
    }

    return response()->json($data);

`

Answer 5

我找到了解决方案.. 我只需要改变视图

<select class="form-control category-list" name="categoryID[{{$language->id}}][]" multiple data-placeholder="Pilih Kategori">
  @foreach($categories as $category)
    <option value="{{$category->id}}">{{$category->CategoryName}}</option>
  @endforeach
</select>

同时更换控制器

$post->categories()->attach($request->categoryID[$this->DEFAULT_LANGUAGE]);

Laravel 保存多对多关系

Laravel save many to many relationship

php

model

laravel

laravel-eloquent