首页 > 解决方案 > 未找到列:1054 未知列“字段列表”中的“taggables.tags_model_id”laravel 雄辩

问题描述

我将实现一个查询来检索我所有的博客及其标签。我正在使用 Laravel Eloquent 多态关系,但我有一个错误Column not found: 1054 Unknown column 'taggables.tags_model_id' in 'field list'。我在 laravel 和我的 SQL 中的所有代码如下所示:

我的桌子:


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
);


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);


create table blog
(
    id          int auto_increment
        primary key,
    title       varchar(200)                        null,
    passage     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);


雄辩的模型


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->morphToMany(TagsModel::class,"taggable");

    }
}


class TagsModel extends BaseModel
{

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

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

}


当我调用此查询时,结果是一个空数组

 public function getItemsWithTags(array $attr)
    {
        return BlogModel::find(1)->tags;
    }

非常感谢你。

标签: phpmysqllaraveleloquentpolymorphic-associations

解决方案


Laravel 的多态关系默认使用反射来确定键列的名称。因为你的模型被调用TagModel,Laravel 假设外键是tag_model_id.

    // Illuminate\Database\Eloquent\Model
    public function getForeignKey()
    {
        return Str::snake(class_basename($this)).'_'.$this->getKeyName();
    }

您可以通过将正确的外键显式传递给morphedByMany方法来解决此问题:

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

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