在php中使用表格从MySQL中按日期分隔的数据

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

// 使用mysqli扩展连接到MySQL数据库
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 使用PDO扩展连接到MySQL数据库
try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e) {
    die("连接失败: " . $e->getMessage());
}

$sql = "SELECT * FROM 表名 ORDER BY 日期字段";
$result = $conn->query($sql);

echo "<table>";
echo "<tr><th>日期</th><th>数据列1</th><th>数据列2</th></tr>";

while($row = $result->fetch_assoc()) {
    echo "<tr>";
    echo "<td>" . $row['日期字段'] . "</td>";
    echo "<td>" . $row['数据列1'] . "</td>";
    echo "<td>" . $row['数据列2'] . "</td>";
    echo "</tr>";
}

echo "</table>";