如何基于关联数据格式化Laravel Collection？

首先纠正下你提供的原始数据结构——PHP数组不允许重复键名，所以实际你的Collection应该是包含多个独立元素的集合，每个元素是带name和districts的数组，正确结构如下：

$originalCollection = collect([
    [
        'name' => 'Test 1 Name',
        'districts' => [
            'district' => '0001',
            'zone' => 'blue'
        ]
    ],
    [
        'name' => 'Test 2 Name',
        'districts' => [
            'district' => '0002',
            'zone' => 'red'
        ]
    ],
    [
        'name' => 'Test 3 Name',
        'districts' => [
            'district' => '0003',
            'zone' => 'yellow'
        ]
    ],
    [
        'name' => 'Test 4 Name',
        'districts' => [
            'district' => '0004',
            'zone' => 'black'
        ]
    ],
    [
        'name' => 'Test 5 Name',
        'districts' => [
            'district' => '0001',
            'zone' => 'green'
        ]
    ]
]);

接下来用Laravel集合的链式方法实现合并逻辑：

$mergedCollection = $originalCollection
    // 按district字段分组
    ->groupBy(fn($item) => $item['districts']['district'])
    // 处理每个分组内的元素
    ->map(function($group, $district) {
        // 保留分组中第一个元素的name
        $targetName = $group->first()['name'];
        // 提取所有zone并去重
        $zones = $group->pluck('districts.zone')->unique()->values();
        
        // 构造最终的districts结构：单个zone用字符串，多个用数组
        $districts = [
            'district' => $district,
            'zone' => $zones->count() > 1 ? $zones->toArray() : $zones->first()
        ];
        
        return ['name' => $targetName, 'districts' => $districts];
    })
    // 重置集合索引为连续数字
    ->values();

执行后得到的$mergedCollection就是你想要的结构：

Collection {#1234
  #items: array:4 [
    0 => array:2 [
      "name" => "Test 1 Name"
      "districts" => array:2 [
        "district" => "0001"
        "zone" => array:2 [
          0 => "blue"
          1 => "green"
        ]
      ]
    ]
    1 => array:2 [
      "name" => "Test 2 Name"
      "districts" => array:2 [
        "district" => "0002"
        "zone" => "red"
      ]
    ]
    2 => array:2 [
      "name" => "Test 3 Name"
      "districts" => array:2 [
        "district" => "0003"
        "zone" => "yellow"
      ]
    ]
    3 => array:2 [
      "name" => "Test 4 Name"
      "districts" => array:2 [
        "district" => "0004"
        "zone" => "black"
      ]
    ]
  ]
}

核心逻辑说明： #

• groupBy：将所有拥有相同district的元素归为一组，方便后续合并
• pluck('districts.zone')->unique()：提取分组内所有zone值并去重，避免重复数据
• 最后根据zone数量决定返回数组还是单个字符串，完全匹配你要的输出格式

内容的提问来源于stack exchange，提问作者Lynx