使用PHP从SQL查询创建JSON

<?php
// 连接到数据库
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 执行SQL查询
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

// 创建空数组
$data = array();

// 遍历结果集
if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        // 将每一行的数据存储到关联数组中
        $data[] = $row;
    }
}

// 将数组转换为JSON字符串
$json = json_encode($data);

// 输出JSON字符串
echo $json;

// 关闭数据库连接
$conn->close();
?>