Update whole table in one query - php

Question

If there's duplicated topic - please, forgive me, but i haven't found a solution yet. First of all, I've got one php file (update.php). This file contains:
<form action='update.php' method='post'>
<table border='1'>
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "exchange";
$conn = new mysqli($servername, $username, $password, $dbname);
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
mysqli_set_charset($conn,"utf8");
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT ID, name, symbol, buy, sell FROM exchangevalues";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
echo "<tr>";
echo "<td><input type='text' name='ID' value='".$row["ID"]."'>";
echo "<td>".$row["name"]."</td>";
echo "<td>Buy: <input type='text' name='buy' value='".$row['buy']."'></td>";
echo "<td>Sell: <input type='text' name='sell' value='".$row['sell']."'></td>";
echo "</tr>";
}
}
$conn->close();
?>
<table>
There's 14 rows and 5 columns in my db. How do i update every row in columns 'buy' and 'sell' on 'click' (isset submit button) with new values? I've tried with ID[], buy[], but I've got problems with loop and i cannot handle it. I'm running MySQL on localhost, also i know that only last row will be updated without running loop, but still...

Answer 1

I am assuming you have corresponding php code to process the input, here is a sample of what you'll need to do for the HTML when creating the form:
if ($result->num_rows > 0) {
$i=0;
while($row = $result->fetch_assoc()) {
echo "<tr>";
echo "<td><input type='text' name='ID[" . $i . "]' value='".$row["ID"]."'>";
echo "<td>".$row["name"]."</td>";
echo "</tr>";
}
}
On the php side to process the input, you can do something like this:
$id_array = $_REQUEST["ID"];
foreach($id_array as $id){
//do insert with $id
}