如何编写PHP文件来更新没有ID或名称的数据库？

我刚开始编写php文件，目前正在尝试创建一个数据库，该数据库存储测量的心率和时间戳

但是，我弄不清楚应该如何编写更新php文件。考虑到我的处境，我的朋友

$statement = mysqli_prepare($con, "UPDATE `User` SET timestamp = ?, heartrate = ?, WHERE ***what to include here*** = ?"); // I am not sure what to include here.

数据库中我的存储数据的代码：

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];
$heartrate = $_POST["heartrate"];




$statement = mysqli_prepare($con, "INSERT INTO `User` (timestamp, heartrate) VALUES (?, ?) ");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");


$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];



$statement = mysqli_prepare($con, "SELECT * FROM `User` WHERE timestamp = ? AND heartrate = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_store_result($statement);


mysqli_stmt_bind_result($statement, $userID, $timestamp, $heartrate);



$user = array();



while(mysqli_stmt_fetch($statement))
{

    $user[timestamp] = $timestamp;

    $user[heartrate] = $heartrate;

}



echo json_encode($user);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];


$statement = mysqli_prepare($con, "UPDATE `User` SET timestamp = ?, heartrate = ?, WHERE username = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);

从数据库获取数据的代码：

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];
$heartrate = $_POST["heartrate"];




$statement = mysqli_prepare($con, "INSERT INTO `User` (timestamp, heartrate) VALUES (?, ?) ");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");


$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];



$statement = mysqli_prepare($con, "SELECT * FROM `User` WHERE timestamp = ? AND heartrate = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_store_result($statement);


mysqli_stmt_bind_result($statement, $userID, $timestamp, $heartrate);



$user = array();



while(mysqli_stmt_fetch($statement))
{

    $user[timestamp] = $timestamp;

    $user[heartrate] = $heartrate;

}



echo json_encode($user);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];


$statement = mysqli_prepare($con, "UPDATE `User` SET timestamp = ?, heartrate = ?, WHERE username = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);

更新数据库的代码：

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];
$heartrate = $_POST["heartrate"];




$statement = mysqli_prepare($con, "INSERT INTO `User` (timestamp, heartrate) VALUES (?, ?) ");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");


$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];



$statement = mysqli_prepare($con, "SELECT * FROM `User` WHERE timestamp = ? AND heartrate = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_store_result($statement);


mysqli_stmt_bind_result($statement, $userID, $timestamp, $heartrate);



$user = array();



while(mysqli_stmt_fetch($statement))
{

    $user[timestamp] = $timestamp;

    $user[heartrate] = $heartrate;

}



echo json_encode($user);



mysqli_stmt_close($statement);



mysqli_close($con);?>

$con = mysqli_connect("server27.000webhost.com" , "a6244607_history" , "123" , "a6244607_history");



$timestamp = $_POST["timestamp"];

$heartrate = $_POST["heartrate"];


$statement = mysqli_prepare($con, "UPDATE `User` SET timestamp = ?, heartrate = ?, WHERE username = ?");


mysqli_stmt_bind_param($statement, "ss", $timestamp, $heartrate);


mysqli_stmt_execute($statement);



mysqli_stmt_close($statement);



mysqli_close($con);

？>

顺便问一下，我的时间戳写对了吗？很抱歉一下子问了这么多问题

希望能尽快得到帮助，谢谢。

1）您不应该在帖子中包含MySQL服务器的凭据

2） 考虑到您只有3个表（用户id、心率、时间戳），在这个准备好的语句中：

UPDATE `User` SET timestamp = ?, heartrate = ?, WHERE ***what to include here*** = ?

您使用时间戳和心率，因此此处要包含的内容应为用户id。 如果要插入一个全新的心率，请使用insert而不是SET

此外，您的声明应该如下所示：

UPDATE `User` SET `timestamp` = ?, `heartrate` = ?, WHERE `user_id` = ?

---

使用桌子名称周围的坟墓（`）。

为什么android被标记为…？您能确切地解释一下您的问题吗？您想从数据库中获取什么？@EnsiehParsaeian我不确定如何为更新编写这句话：$statement=mysqli_prepare（$con，“update

User

SET timestamp=？，heartrate=？，此处包含的内容=？”；与之前的更新一样，我是这样写的：$statement=mysqli_prepare（$con，“update

User

SET timestamp=？，heartrate=？，WHERE username=？”；任何想法如何改变，因为现在我没有一个字段，它寻找更新。。。如果我的解释不好，很抱歉。@Razgriz，因为我正在用android studio进行此操作。。。堆栈溢出的新功能抱歉…请在where子句中使用表的主键，或者使用具有唯一值的列。如果用户名是PK或unique，您可以使用它。