Select Data by Id PHP - php

Question

I have trouble to select a set of specific data using ID from the database. For example, employee one has a unique id of e000000001, when I click the view button in the index will lead to employee detail page which shows the detail of that particular employee instead of all the employees' detail. Thank you.
//from index.php page
<?php
require_once 'db/dbEmpList.php';
$sqlStr = "SELECT * FROM employees;";
$result = $connection->query($sqlStr);
if ($result->num_rows > 0) {
echo "<table class='table table-sm'><thread><tr><th>Full Name</th><th>Employee ID</th><th>Position</th><th>View Employee's Details</th></tr>";
while ($row = $result->fetch_assoc()) {
echo "<tr><td>"
. $row["empName"]. "</td><td>"
. $row["empID"]. "</td><td>"
. $row["position"]. "</td>"
. "<td> <a href='employeedetail.php?id={$row["empID"]}'>View</a>"
. "</td></tr>";
}
}
// from employee page
require_once 'db/dbEmpDetail.php';
$sql = "SELECT * FROM employees where empID = '{$row["empID"]}' ";
$result = mysqli_query($connection, $sql);
if (mysqli_num_rows($result)) {
while ($row = mysqli_fetch_assoc($result)) {
echo '<tr>' .'<td>' .$row["empName"].'</td>'.'<td>'. $row["position"].'</td>' .'<td>'.$row["empNRIC"].'</td>' .'<td>'.$row["empID"].'</td>' .'<td>'.$row["empEmail"].'</td>' .'<td>'.$row["empPwd"].'</td>' . "</tr>";
}
} else {
echo "0 results";
}
mysqli_close($connection);
?>

Answer 1

// FROM EMPLOYEE PAGE
The way you retrieve URL query string is wrong. You should be using $_GET to get the query string from URL. In your case it should be $_GET['id']. See the code below:
require_once 'db/dbEmpDetail.php';
$employeeid = trim(mysqli_real_escape_string($_GET['id']));
$sql = "SELECT * FROM employees where empID = '".$employeeid."' ";
$result = mysqli_query($connection, $sql);
if (mysqli_num_rows($result)) {
while ($row = mysqli_fetch_assoc($result)) {
echo '<tr>' .'<td>' .$row["empName"].'</td>'.'<td>'. $row["position"].'</td>' .'<td>'.$row["empNRIC"].'</td>' .'<td>'.$row["empID"].'</td>' .'<td>'.$row["empEmail"].'</td>' .'<td>'.$row["empPwd"].'</td>' . "</tr>";
}
}
else {
echo "0 results";
}
mysqli_close($connection);
?>