php - Laravel-SQLSTATE[23000] : Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails

Question

我正在 Laravel 中构建一个项目，尝试在数据库中保存我设置的模型内容的记录，如下所示:

class Content extends Model
{
    /**
     * The attributes that are guarded by mass assignable.
     *
     * @var array
     */
    protected $guarded = [
        'id'
    ];

    public function contentType()
    {
        return $this->hasOne('App\ContentType');
    }
}

在我的 Controller 中，我首先将记录保存在 content_types 表中，如下所示:

    public function resolveType($type)
    {
        return ContentType::firstOrCreate(
          ['name' => $type,
          'slug' => str_slug($type, '-')]
        );
    }

然后我保存内容:

        Content::create([
          'ct_id' => $post->ID,
          'cms_id' => '',
          'title' => $post->post_title,
          'slug' => str_slug($post->post_title, '-'),
          'excerpt' => $post->post_excerpt,
          'body' => $this->formatBodyImages($post->post_content),
          'password' => $post->post_password,
          'parent_id' => $post->post_parent,
        ]);

ContentType 模型的设置如下:

class ContentType extends Model
{
    /**
     * The attributes that are guarded by mass assignable.
     *
     * @var array
     */
    protected $guarded = [
        'id'
    ];

    public function contents()
    {
        return $this->hasMany('App\Content', 'ct_id');
    }
}

因此，当我尝试保留新内容记录时，出现错误:

SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (middleton.contents, CONSTRAINT contents_ct_id_foreign FOREIGN KEY (ct_id) REFERENCES content_types (id)) (SQL: insert into contents (cms_id, title, slug, excerpt, body, password, parent_id, updated_at, created_at)

Answer 1

看起来$post->ID为空，并且数据库中有具有指定ID的ContentType。也许您正在尝试这样做？

'ct_id' => $post->id,

您可以使用dd($post)命令检查$post变量的内容。

如果 $post->id 为您提供正确的值(它不为空并且存在于表中)，则尝试使用 fillable 数组以及所有列出的属性使用 protected 数组。