PHP教程：将静态关联数组高效合并到动态列表的每个元素中

[
    {
        "user_id": "1",
        "name": "test 1"
    },
    {
        "user_id": "2",
        "name": "test 2"
    },
    {
        "user_id": "3",
        "name": "test 3"
    }
]

$staticData = [
    "student_list" => [
        ["stu_id" => 1, "name" => "abc"],
        ["stu_id" => 2, "name" => "xyz"]
    ],
    "class" => "12th",
    "average_score" => "5",
    "results" => [
        ["result_date" => "2012-12-13", "city" => "city 1"],
        ["result_date" => "2015-10-13", "city" => "city 2"]
    ]
];

[
    {
        "user_id": "1",
        "name": "test 1",
        "student_list": [ /* ... */ ],
        "class": "12th",
        "average_score": "5",
        "results": [ /* ... */ ]
    },
    {
        "user_id": "2",
        "name": "test 2",
        "student_list": [ /* ... */ ],
        "class": "12th",
        "average_score": "5",
        "results": [ /* ... */ ]
    }
    // ... 其他用户记录
]

<?php

// 模拟从数据库获取的JSON格式用户数据
// 实际应用中，$valueJson 可能来自 $this->TestModel->get_user_details($userIds);
$valueJson = '[
    {
        "user_id": "1",
        "name": "test 1"
    },
    {
        "user_id": "2",
        "name": "test 2"
    },
    {
        "user_id": "3",
        "name": "test 3"
    }
]';

// 定义需要合并到每个用户记录中的静态数据
$staticDataToMerge = [
    "student_list" => [
        ["stu_id" => 1, "name" => "abc"],
        ["stu_id" => 2, "name" => "xyz"]
    ],
    "class" => "12th",
    "average_score" => "5",
    "results" => [
        ["result_date" => "2012-12-13", "city" => "city 1"],
        ["result_date" => "2015-10-13", "city" => "city 2"]
    ]
];

// 1. 将JSON字符串解码为PHP关联数组
$decodedArray = json_decode($valueJson, true);

// 检查解码是否成功且为数组，并进行错误处理
if (json_last_error() !== JSON_ERROR_NONE || !is_array($decodedArray)) {
    die("JSON解码失败或数据格式不正确: " . json_last_error_msg() . "\n");
}

// 2. 遍历每个用户记录并合并静态数据
for ($i = 0; $i < count($decodedArray); $i++) {
    // array_merge 将 $decodedArray[$i] 和 $staticDataToMerge 合并。
    // 如果键名相同，$staticDataToMerge 中的值会覆盖 $decodedArray[$i] 中的值。
    // 在本例中，原始数据键（user_id, name）与静态数据键不冲突，因此会追加。
    $decodedArray[$i] = array_merge($decodedArray[$i], $staticDataToMerge);
}

// 3. 将修改后的PHP数组重新编码回JSON字符串
// JSON_PRETTY_PRINT 使输出更易读
// JSON_UNESCAPED_UNICODE 确保中文字符不被转义
$finalJson = json_encode($decodedArray, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);

echo $finalJson;

?>