PHP如何按组/部门/团队分组数组，避免覆盖同一行？

原数组结构 #

$original_array = [
    [
        "group" => "g1",
        "department" => "d1",
        "team" => null,
        "data_col1" => "some_data1",
        "data_col2" => "some_data2"
    ],
    [
        "group" => "g1",
        "department" => "d1",
        "team" => null,
        "data_col1" => "some_data3",
        "data_col2" => "some_data4"
    ],
    [
        "group" => "g1",
        "department" => "d1",
        "team" => "t3",
        "data_col1" => "some_data5",
        "data_col2" => "some_data6"
    ],
    [
        "group" => "g4",
        "department" => "d6",
        "team" => "t11",
        "data_col1" => "some_data7",
        "data_col2" => "some_data8"
    ]
];

预期分组结果 #

[
    0 => [
        "group" => "g1",
        "department" => "d1",
        "team" => null,
        "data" => [
            0 => ["data_col1" => "some_data1", "data_col2" => "some_data2"],     
            1 => ["data_col1" => "some_data3", "data_col2" => "some_data4"]
        ]
    ],
    1 => [
        "group" => "g1",
        "department" => "d1",
        "team" => "t3",
        "data" => [
            0 => ["data_col1" => "some_data5", "data_col2" => "some_data6"]                   
        ]
    ],  
    2 => [
        "group" => "g4",
        "department" => "d6",
        "team" => "t11",
        "data" => [
            0 => ["data_col1" => "some_data7", "data_col2" => "some_data8"]
        ]
    ]
]

错误实现代码 #

$new_array = [];

foreach ($original_array as $row) {
    foreach ($row as $key => $value) {
        if ($key === "group" || $key === "department" || $key === "team") {
            $new_array[$key] = $value;
        } else {
            $new_array[] = $value;
        }
    }
}

实际错误结果 #

[
    "group" => "g4",
    "department" => "d6",
    "team" => "t11",
    0 => "some_data1",
    1 => "some_data2",
    2 => "some_data3",
    3 => "some_data4",
    4 => "some_data5",
    5 => "some_data6",
    6 => "some_data7",
    7 => "some_data8"
]

问题原因 #

• 分组信息被覆盖：每次循环一行数据时，直接给$new_array的group/department/team键赋值，新值会替换旧值，最终只保留最后一行的分组信息。
• 数据未归类：将data_col1/data_col2直接追加到$new_array的根层级，没有按分组存入对应的data子数组，导致数据零散分布。
• 未区分不同分组：全程复用同一个$new_array结构，没有为每个独立的分组创建单独的数组项，无法区分不同分组的内容。

修正后的代码 #

$original_array = [
    [
        "group" => "g1",
        "department" => "d1",
        "team" => null,
        "data_col1" => "some_data1",
        "data_col2" => "some_data2"
    ],
    [
        "group" => "g1",
        "department" => "d1",
        "team" => null,
        "data_col1" => "some_data3",
        "data_col2" => "some_data4"
    ],
    [
        "group" => "g1",
        "department" => "d1",
        "team" => "t3",
        "data_col1" => "some_data5",
        "data_col2" => "some_data6"
    ],
    [
        "group" => "g4",
        "department" => "d6",
        "team" => "t11",
        "data_col1" => "some_data7",
        "data_col2" => "some_data8"
    ]
];

$grouped = [];

foreach ($original_array as $item) {
    // 用group、department、team拼接唯一标识键，处理null值避免键冲突
    $key = implode('|', [
        $item['group'],
        $item['department'],
        is_null($item['team']) ? 'null' : $item['team']
    ]);
    
    if (!isset($grouped[$key])) {
        // 初始化新分组的结构
        $grouped[$key] = [
            'group' => $item['group'],
            'department' => $item['department'],
            'team' => $item['team'],
            'data' => []
        ];
    }
    
    // 将当前行的业务数据添加到对应分组的data数组
    $grouped[$key]['data'][] = [
        'data_col1' => $item['data_col1'],
        'data_col2' => $item['data_col2']
    ];
}

// 转换为索引数组（移除关联键，符合预期结果的结构）
$new_array = array_values($grouped);

print_r($new_array);

代码说明 #

1. 生成唯一分组键：用group、department、team拼接成唯一字符串，作为临时分组的标识，处理null值避免键冲突。
2. 初始化分组结构：如果当前分组不存在，创建包含分组信息和空data数组的结构。
3. 归集业务数据：将每行的data_col1/data_col2存入对应分组的data子数组。
4. 转换为索引数组：通过array_values移除临时的关联键，得到预期的索引数组结构。

运行以上代码，输出结果与预期完全一致。

内容的提问来源于stack exchange，提问作者pileup