如何在数据库中使用eloquent laravel保存标签列表数组？

Question

我打算在我的表格内保存一个带有一些标签的帖子，但我无法保存与这个新帖子相关的标签列表。我有一个Blog、Tag、Taggable的表格，呈现在下面。

-- auto-generated definition
create table blog
(
    id          int auto_increment
        primary key,
    title       varchar(200)                        null,
    content     text                                null,
    author      varchar(200)                        null,
    category    varchar(200)                        null,
    img_url     varchar(200)                        null,
    created_at  timestamp default CURRENT_TIMESTAMP not null,
    updated_at  timestamp                           null,
    deleted_at  timestamp                           null,
    user_id     int                                 not null,
    category_id int                                 null,
    constraint fk18
        foreign key (user_id) references users (id)
            on update cascade on delete cascade,
    constraint fk19
        foreign key (category_id) references blog (id)
            on update cascade on delete cascade
);

create index blog_index
    on blog (category_id);

create index blog_users_index
    on blog (user_id);

-- auto-generated definition
create table tags
(
    id         int auto_increment
        primary key,
    name       varchar(200)                        null,
    created_at timestamp default CURRENT_TIMESTAMP not null,
    updated_at timestamp                           null,
    deleted_at timestamp                           null
);

-- auto-generated definition
create table taggables
(
    id            int auto_increment
        primary key,
    tag_id        int                                 null,
    taggable_type varchar(512)                        null,
    taggable_id   int                                 null,
    created_at    timestamp default CURRENT_TIMESTAMP not null,
    updated_at    timestamp                           null,
    deleted_at    timestamp                           null,
    constraint fk23
        foreign key (tag_id) references tags (id)
            on update cascade on delete cascade
);

create index taggables_tag_id_index
    on taggables (tag_id);

而这是我的这些表格的雄辩模型。

class BaseModel extends Model
{
    protected $table;
    protected $primaryKey;


    use SoftDeletes;

}



class BlogModel extends BaseModel
{

    protected $table = 'blog';
    protected $primaryKey = 'id';


    public function tags()
    {
        return $this->morphedByMany(TagsModel::class,'taggable', null, 'tag_id');
    }
}

class TagsModel extends BaseModel
{

    protected $table = 'tags';
    protected $primaryKey = 'id';

    public function blog()
    {
        return $this->morphedByMany(BlogModel::class,"taggable");
    }


}

的 save() 是用来将一个帖子和它的标签保存到数据库中。

  public function save($model, $title, $passage, $author, $category, $category_id, $img_url, $tag, $user_id)
    {
        $model->title = $title;
        $model->content = $passage;
        $model->author = $author;
        $model->category = $category;
        $model->category_id = $category_id;
        $model->img_url = $img_url;
        $model->user_id = $user_id;
        $model->save();
        return $model->tags()->saveMany($tag);
    }

在这里，我创建了一个标签列表，例如： ['tag1','tag2','tag3'] 传给 save() 的方法，就是上面介绍的。

    private function tags($tags)
    {
        $tag = array();
        foreach ($tags as $t)
            array_push($tag,['name' => $t]);


        return $tag;
    }

最后，错误是

Argument 1 passed to Illuminate\Database\Eloquent\Relations\BelongsToMany::save() must be an instance of Illuminate\Database\Eloquent\Model, array given, called in /var/www/test/vendor/illuminate/database/Eloquent/Relations/BelongsToMany.php on line 946 and defined in /var/www/test/vendor/illuminate/database/Eloquent/Relations/BelongsToMany.php on line 927

Answer 1

你需要建立这样的标签数组。

    private function tags($tags)
    {
        $tag = array();
        foreach ($tags as $t)
            $tag[] = new TagsModel(['name' => $t]);


        return $tag;
    }

Answer 2

我把模型改成这样就解决了问题：

class BlogModel extends BaseModel
{

    protected $table = 'blog';
    protected $primaryKey = 'id';


    public function tags()
    {
        return $this->morphToMany(TagsModel::class,'taggable',null,null,'tag_id');
    }
}

class TagsModel extends BaseModel
{

    protected $table = 'tags';
    protected $primaryKey = 'id';

    protected $fillable = ['name'];
    public function blog()
    {
        return $this->morphedByMany(BlogModel::class,"taggable");
    }


}

而且我还从taggables中删除了主键和外键。

create table taggables
(
    tag_id        int                                 null,
    taggable_id   int                                 null,
    taggable_type varchar(512)                        null,
    created_at    timestamp default CURRENT_TIMESTAMP null,
    deleted_at    timestamp                           null,
    updated_at    timestamp                           null
);