在while循环之前从mysqli查询中回显变量

Question

<?php
if (isset($_GET['cid'])) {
    $id = ($_GET['cid']);
} else {
    echo 
    "Deze client is nog niet juist aangemaakt.";
}
$sql = "SELECT * FROM forms WHERE Client_ID ='$id'";
$result = $con->query($sql);
if (mysqli_num_rows($result) > 0) {
$username = 'how to get this value here ?';
echo $username; 
            while($row = mysqli_fetch_array($result)) {

This is my code. I want show the username of the user and in the while loop all the data that has been collected over the years. Just like a header above all data. I am farely new to php and mysqli. Can anyone help me how to get the username out of the table and echo it before the while loop ?

Answer 1

To do this you need to first fetch all the data from the result set. You can usefetch_all() if you expect multiple rows, else you can optimize with fetch_array() .

Then you can access the row at index 0 and its key to get the value from the column you want. If there are no rows or the column is not part of your SQL then you can default it to an empty string.

<?php
if (isset($_GET['cid'])) {
    $id = $_GET['cid'];
} else {
    echo "Deze client is nog niet juist aangemaakt.";
}

$stmt = $con->prepare("SELECT * FROM forms WHERE Client_ID = ?");
$stmt->bind_param('s', $id);
$stmt->execute();
$result = $stmt->get_result();
$data = $result->fetch_all(MYSQLI_ASSOC);

// if there is at least one row and there is a key username then use it else empty string
$username = $data[0]['username'] ?? '';

echo $username;

// if you need to loop the rows:
foreach($data as $row) {

}

For a beginner, you should really look into learning PDO instead of mysqli.