使用Php查询SQL并输出GeoPolygon的geojson

$servername = "数据库服务器地址";
$username = "用户名";
$password = "密码";
$dbname = "数据库名";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

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

$sql = "SELECT geo_polygon_column FROM your_table";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 处理查询结果
    while($row = $result->fetch_assoc()) {
        $geo_polygon = $row["geo_polygon_column"];
        // 进一步处理GeoPolygon数据
    }
} else {
    echo "没有查询到结果";
}

// 假设GeoPolygon数据是一个包含多个坐标点的字符串，每个坐标点由经度和纬度组成，以逗号分隔
$geo_polygon = "经度1,纬度1,经度2,纬度2,经度3,纬度3,...";

// 解析GeoPolygon数据
$coordinates = explode(",", $geo_polygon);

// 构建geojson结构
$geojson = array(
    "type" => "Feature",
    "geometry" => array(
        "type" => "Polygon",
        "coordinates" => array(
            array_chunk($coordinates, 2) // 将坐标点分组为经度和纬度对
        )
    )
);

// 将geojson转换为JSON字符串
$geojson_string = json_encode($geojson);

// 输出geojson
echo $geojson_string;

$conn->close();