解析PHP中的多维数组项

Question

我正在创建一家电子商务网站，需要在特定数组中提供商店所拥有的类别。目前从mysql表中检索到的数据如果数组具有不同的子类，则包含相同类别ID的不同数组项。我必须将相同类别ID收集在同一个数组中，并为子类创建嵌套数组。此代码位于laravel 4.2上。以下是当前数据格式：

"data": [
    {
      "id": 1,
      "name": "Fruits",
      "sub_category_names": [
        "Dairy Whiteners"
      ],
      "total_items": 69
    },
    {
      "id": 1,
      "name": "Fruits",
      "sub_category_names": [
        "Tea & Coffee"
      ],
      "total_items": 69
    },
    {
      "id": 1,
      "name": "Fruits",
      "sub_category_names": [
        "Concentrates - Tang etc"
      ],
      "total_items": 69
    },
    {
      "id": 2,
      "name": "Beverages",
      "sub_category_names": [
        "Tea & Coffee"
      ],
      "total_items": 28
    },
    {
      "id": 2,
      "name": "Beverages",
      "sub_category_names": [
        "Concentrates - Tang etc"
      ],
      "total_items": 28
    }
  ]

Here is what I need ,

"data": [
    {
      "id": 1,
      "name": "Fruits",
      "sub_category_names": [
        "Dairy Whiteners" , "Concentrates - Tang etc" , "Tea & Coffee"
      ],
      "total_items": 69
    } ,

    {
      "id": 2,
      "name": "Beverages",
      "sub_category_names": [
        "Tea & Coffee" , "Concentrates - Tang etc"
      ],
      "total_items": 28
    }
  ]

The code I wrote for the above ,

// For the current categories create a common array for subcategories for same categories
        $filteringSelectedCategories = [];
        $subCategoriesNamesLocal = [];
        $innerIndex = 0;
        for ($i = 0; $i < count($selectedCategories); $i++) {

            // to prevent undefined offset error
            if (!isset($selectedCategories[$i + 1])) {
                continue ;
                // if 6 don't exist then deal with 5
            }
            // if the id of two items is same then push that sub category name in the same array
            if ($selectedCategories[$i]['id'] === $selectedCategories[$i + 1]['id']) {
                array_push($subCategoriesNamesLocal, $selectedCategories[$i]['sub_category_names']);
            } 
            // if the id is different then push the array values with the sub category name in an array 
            else {

                $filteringSelectedCategories[$innerIndex]['id'] = $selectedCategories[$i]['id'];
                $filteringSelectedCategories[$innerIndex]['name'] = $selectedCategories[$i]['name'];
                $filteringSelectedCategories[$innerIndex]['sub_category_names'] = $subCategoriesNamesLocal;
                $filteringSelectedCategories[$innerIndex]['total_items'] = $selectedCategories[$i]['total_items'];

                // nullify the array after assigning the value
                $subCategoriesNamesLocal = [];
                // increment the new array index
                $innerIndex = $innerIndex + 1;

            }
        }

以下是我从上述代码中获得的输出结果：

"data": [
    {
      "id": 1,
      "name": "Fruits",
      "sub_category_names": [
        [
          "Dairy Whiteners"
        ],
        [
          "Tea & Coffee"
        ]
      ],
      "total_items": 69
    }
  ]

- Siddharth Sharma

---

如果你正在使用MySQL，我认为GROUP_CONCAT可以解决这个问题。请展示一下你如何获取数据。 - Mihai

Answer 1

我不完全确定偏移错误可能会出现什么情况，但我相信你可以轻松解决；

foreach ($selectedCategories as $key => $data) {
    $newKey = $data['id'];
    $filteringSelectedCategories[$newKey]['id'] = $data['id'];
    $filteringSelectedCategories[$newKey]['name'] = $data['name'];
    $filteringSelectedCategories[$newKey]['sub_category_names'][] = $data['sub_category_names'];
    $filteringSelectedCategories[$newKey]['total_items'] = $data['total_items'];
}

- glend

---

PHP有foreach来迭代数组中的元素，而不是使用for。 - Siddharth Sharma

以下是我在应用上述解决方案后得到的工作结果："data":[ { "id":1, "name":"水果", "sub_category_names":[ "奶精", "茶和咖啡", "浓缩饮料-Tang等" ], "total_items":69 }, { "id":2, "name":"饮料", "sub_category_names":[ "茶和咖啡", "浓缩饮料-Tang等" ], "total_items":28 } ] - Siddharth Sharma

抱歉，我的错。已经更新帖子为foreach。感谢你的指出。 - glend

Answer 2

你不能直接在 $subCategoriesNamesLocal 中进行数组推送，因为你正在嵌套数组。请先创建一个数组，然后将其连接到该字段。

- Marcos Pérez Gude

Answer 3

试试这个：

// For the current categories create a common array for subcategories for same categories
        $filteringSelectedCategories = [];
        $subCategoriesNamesLocal = [];
        $innerIndex = 0;
        for ($i = 0; $i < count($selectedCategories); $i++) {

            // to prevent undefined offset error
            if (!isset($selectedCategories[$i + 1])) {
                continue ;
                // if 6 don't exist then deal with 5
            }
            // if the id of two items is same then push that sub category name in the same array
            if ($selectedCategories[$i]['id'] === $selectedCategories[$i + 1]['id']) {
                array_push($subCategoriesNamesLocal, $selectedCategories[$i]['sub_category_names']);
            } 
            // if the id is different then push the array values with the sub category name in an array 
            else {

                $filteringSelectedCategories[$innerIndex]['id'] = $selectedCategories[$i]['id'];
                $filteringSelectedCategories[$innerIndex]['name'] = $selectedCategories[$i]['name'];
                $filteringSelectedCategories[$innerIndex]['sub_category_names'] = '"' . implode('","', $subCategoriesNamesLocal) . '"';

}
                $filteringSelectedCategories[$innerIndex]['total_items'] = $selectedCategories[$i]['total_items'];

                // nullify the array after assigning the value
                $subCategoriesNamesLocal = [];
                // increment the new array index
                $innerIndex = $innerIndex + 1;

            }
        }

- sribasu