README

简介

这个 HasManyThrough 扩展版本允许与无限中间模型建立关系。
它支持 多对多 和 多态 关系以及所有可能的组合。
支持 Laravel 5.5.29+。

安装

composer require hamid09430/direct-nested-relation-object:1.1

用法

• HasMany
• BelongsToMany
• MorphMany
• MorphToMany
• MorphedByMany
• BelongsTo
• 现有关系
• HasOneDeep
• 中间和关联数据
• 表别名
• 软删除

HasMany

使用 文档示例 并增加一个层级
Country → has many → User → has many → Post → has many → Comment

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function comments()
    {
        return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post']);
    }
}

与 hasManyThrough() 一样，hasManyDeep() 的第一个参数是相关模型。第二个参数是一个数组，包含从远端父模型（定义关系的模型）到相关模型的中间模型。

默认情况下，hasManyDeep() 使用 Eloquent 的外键和本地键约定。您还可以指定自定义外键作为第三个参数，并指定自定义本地键作为第四个参数

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function comments()
    {
        return $this->hasManyDeep(
            'App\Comment',
            ['App\User', 'App\Post'], // Intermediate models, beginning at the far parent (Country).
            [
               'country_id', // Foreign key on the "users" table.
               'user_id',    // Foreign key on the "posts" table.
               'post_id'     // Foreign key on the "comments" table.
            ],
            [
              'id', // Local key on the "countries" table.
              'id', // Local key on the "users" table.
              'id'  // Local key on the "posts" table.
            ]
        );
    }
}

您可以使用 null 代替默认键

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function comments()
    {
        return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'], [null, 'custom_user_id']);
    }
}

BelongsToMany

您可以在中间路径中包含 BelongsToMany 关系。

使用 文档示例 并增加一个层级
User → belongs to many → Role → has many → Permission

将连接表添加到中间模型中

class User extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function permissions()
    {
        return $this->hasManyDeep('App\Permission', ['role_user', 'App\Role']);
    }
}

如果您指定了自定义键，请记住在连接表的“右侧”交换外键和本地键

class User extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function permissions()
    {
        return $this->hasManyDeep(
            'App\Permission',
            ['role_user', 'App\Role'], // Intermediate models and tables, beginning at the far parent (User).
            [           
               'user_id', // Foreign key on the "role_user" table.
               'id',      // Foreign key on the "roles" table (local key).
               'role_id'  // Foreign key on the "permissions" table.
            ],
            [          
              'id',      // Local key on the "users" table.
              'role_id', // Local key on the "role_user" table (foreign key).
              'id'       // Local key on the "roles" table.
            ]
        );
    }
}

MorphMany

您可以在中间路径中包含 MorphMany 关系。

使用 文档示例 并增加一个层级
User → has many → Post → morph many → Comment

将多态外键指定为数组，从 *_type 列开始

class User extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function postComments()
    {
        return $this->hasManyDeep(
            'App\Comment',
            ['App\Post'],
            [null, ['commentable_type', 'commentable_id']]
        );
    }
}

MorphToMany

您可以在中间路径中包含 MorphToMany 关系。

使用 文档示例 并增加一个层级
User → has many → Post → morph to many → Tag

将连接表添加到中间模型中，并将多态外键指定为数组，从 *_type 列开始

class User extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function postTags()
    {
        return $this->hasManyDeep(
            'App\Tag',
            ['App\Post', 'taggables'],
            [null, ['taggable_type', 'taggable_id'], 'id'],
            [null, null, 'tag_id']
        );
    }
}

请记住在连接表的“右侧”交换外键和本地键

MorphedByMany

您可以在中间路径中包含 MorphedByMany 关系。

使用 文档示例 并增加一个层级
Tag → morphed by many → Post → has many → Comment

将连接表添加到中间模型中，并将多态本地键指定为数组，从 *_type 列开始

class Tag extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function postComments()
    {
        return $this->hasManyDeep(
            'App\Comment',
            ['taggables', 'App\Post'],
            [null, 'id'],
            [null, ['taggable_type', 'taggable_id']]
        );
    }
}

BelongsTo

您可以在中间路径中包含 BelongsTo 关系
Tag → morphed by many → Post → belongs to → User

交换外键和本地键

class Tag extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function postAuthors()
    {
        return $this->hasManyDeep(
            'App\User',
            ['taggables', 'App\Post'],
            [null, 'id', 'id'],
            [null, ['taggable_type', 'taggable_id'], 'user_id']
        );
    }
}

现有关系

在复杂情况下，您可以通过链式调用现有关系来定义 HasManyDeep 关系

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function comments()
    {
        return $this->hasManyDeepFromRelations($this->posts(), (new Post)->comments());
    }

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

class Post extends Model
{
    public function comments()
    {
        return $this->hasMany('App\Comment');
    }
}

HasOneDeep

如果只想检索一个相关实例，请使用 HasOneDeep 关系

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function latestComment()
    {
        return $this->hasOneDeep('App\Comment', ['App\User', 'App\Post'])
            ->latest('comments.created_at');
    }
}

中间和关联数据

使用 withIntermediate() 来检索中间表的属性

public function comments()
{
    return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'])
        ->withIntermediate('App\Post');
}

foreach ($country->comments as $comment) {
    // $comment->post->title
}

默认情况下，这将检索表的所有列。请注意，这将执行一个单独的查询来获取列列表。

您可以将选择的列作为第二个参数指定

public function comments()
{
    return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'])
        ->withIntermediate('App\Post', ['id', 'title']);
}

作为第三个参数，您可以指定一个自定义访问器

public function comments()
{
    return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'])
        ->withIntermediate('App\Post', ['id', 'title'], 'accessor');
}

foreach ($country->comments as $comment) {
    // $comment->accessor->title
}

如果您从多个表中检索数据，您可以使用嵌套访问器

public function comments()
{
    return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'])
        ->withIntermediate('App\Post')
        ->withIntermediate('App\User', ['*'], 'post.user');
}

foreach ($country->comments as $comment) {
    // $comment->post->title
    // $comment->post->user->name
}

对于 BelongsToMany 和 MorphToMany/MorphedByMany 关系的交叉表，请使用 withPivot()

public function permissions()
{
    return $this->hasManyDeep('App\Permission', ['role_user', 'App\Role'])
        ->withPivot('role_user', ['expires_at']);
}

foreach ($user->permissions as $permission) {
    // $permission->role_user->expires_at
}

您可以将自定义交叉模型作为第三个参数，并将自定义访问器作为第四个参数指定

public function permissions()
{
    return $this->hasManyDeep('App\Permission', ['role_user', 'App\Role'])
        ->withPivot('role_user', ['expires_at'], 'App\RoleUserPivot', 'pivot');
}

foreach ($user->permissions as $permission) {
    // $permission->pivot->expires_at
}

表别名

如果您的关联路径包含相同的模型多次，您可以指定一个表别名

class Post extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function childComments()
    {
        return $this->hasManyDeep('App\Comment', ['App\Comment as alias'], [null, 'parent_id']);
    }
}

在使用别名的模型中，请使用 HasTableAlias 特性

class Comment extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasTableAlias;
}

软删除

默认情况下，软删除的中间模型将不包括在结果中。使用 withTrashed() 来包含它们

class Country extends Model
{
    use \Staudenmeir\EloquentHasManyDeep\HasRelationships;

    public function comments()
    {
        return $this->hasManyDeep('App\Comment', ['App\User', 'App\Post'])
            ->withTrashed('users.deleted_at');
    }
}

class User extends Model
{
    use SoftDeletes;
}