php执行多条mysql查询语句

try {
    $conn = new mysqli($servername, $username, $password, $dbname);
    if ($conn->connect_error) {
        die("连接失败: " . $conn->connect_error);
    }
    $sql = "SELECT * FROM table_name";
    $result = $conn->query($sql);
    if ($result === FALSE) {
        die("查询失败: " . $conn->error);
    }
} catch (Exception $e) {
    echo "异常: " . $e->getMessage();
}
$conn->close();

$stmt = $conn->prepare("SELECT * FROM table_name WHERE id = ?");
$stmt->bind_param("i", $id);
$stmt->execute();
$result = $stmt->get_result();

$conn->begin_transaction();
try {
    $conn->query("UPDATE table1 SET column1 = 'value' WHERE id = 1");
    $conn->query("UPDATE table2 SET column2 = 'value' WHERE id = 2");
    $conn->commit();
} catch (Exception $e) {
    $conn->rollback();
    echo "事务失败: " . $e->getMessage();
}