使用 groupBy 函数导致 Laravel JSON 格式出错答案

【问题标题】：Laravel JSON format is coming wrong by using groupBy function使用 groupBy 函数导致 Laravel JSON 格式出错
【发布时间】：2019-07-07 17:54:02
【问题描述】：

我创建了一个 API 资源，它使用 groupBy 方法返回特定导师的选定主题和类别，

问题是，groupBy 方法没有像我预期的那样发送响应。

请在下面找到当前和预期的响应，

当前 API 响应

"Web Design": [
                {
                    "id": 542,
                    "name": "WordPress",
                    "category_name": "Web Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 70,
                    }
                },
                {
                    "id": 542,
                    "name": "WordPress",
                    "category_name": "Web Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 70,
                    }
                }
],
"Graphic Design": [
                {
                    "id": 547,
                    "name": "Photoshop",
                    "category_name": "Graphic Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 71,
                    }
                },
                {
                    "id": 548,
                    "name": "WordPress",
                    "category_name": "Graphic Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 71,
                    }
                }
]

groupBy 功能：

$subjects = $this->tutor->subjects->map(function($subject){
            $subject->category_name = SubjectCategory::find($subject->pivot->subject_category_id)->name;
            return $subject;
        });
        $subjectData = $subjects->groupBy('category_name');

预期的 API 响应

"category": "Web Design",
"subjects": [
                {
                    "id": 542,
                    "name": "WordPress",
                    "category_name": "Web Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 70,
                    }
                },
                {
                    "id": 542,
                    "name": "WordPress",
                    "category_name": "Web Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 70,
                    }
                }
],
"category": "Graphic Design",
"subjects": [
                {
                    "id": 547,
                    "name": "Photoshop",
                    "category_name": "Graphic Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 71,
                    }
                },
                {
                    "id": 548,
                    "name": "WordPress",
                    "category_name": "Graphic Design",
                    "pivot": {
                        "tutor_id": 4,
                        "subject_id": 542,
                        "subject_category_id": 71,
                    }
                }
]

请查找主题类别、主题和主题类别表的给定迁移。

迁移：主题类别

Schema::create('subject_categories', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('slug');
            $table->integer('parent_id')->nullable();
            $table->unsignedTinyInteger('is_deleted')->default(SubjectCategory::IS_DELETED);
            $table->timestamps();
        });

迁移：CreateSubjectsTable

Schema::create('subjects', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('slug');
            $table->integer('isActive');
            $table->timestamps();
        });

迁移：CreateSubjectSubjectCategoryTable

Schema::create('subject_subject_category', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('subject_id')->unsigned();
            $table->integer('subject_category_id')->unsigned();
        });

        Schema::table('subject_subject_category', function($table) {
            $table->foreign('subject_id')->references('id')->on('subjects');
            $table->foreign('subject_category_id')->references('id')->on('subject_categories');
        });

提前感谢您的帮助。

【问题讨论】：

如果你能发布你的表格结构会很好。
嗨，@ZeshanKhattak 我已经在问题中添加了迁移

标签： laravel eloquent laravel-5.6 jsonapi-resources

【解决方案1】：

当在 Collection 实例上使用 groupBy() 方法时，Laravel 的响应正是它应该是的。

此外，您的“预期”JSON 响应无效。您不能多次使用相同的属性名称，因为您只会得到最后定义的值（例如，最后一个类别属性将覆盖之前的类别属性——与主题相同）。您至少需要将它们分组到自己的数组中。

[
    "category": "Web Design",
    "subjects": [...]
],
[
    "category": "Graphic Design",
    "subjects": [...]
],

这个输出可以通过对查询结果进行一些简单的格式化来实现。

$formatted_response = [];
foreach ($subjectData as $category => $subjects) {
    $formatted_response[] = [
        'category' => $category,
        'subjects' => $subjects
    ];
}
return response()->json($formatted_response);

我希望这会有所帮助，祝你好运！

【讨论】：

太好了……非常感谢