Error in SQL Syntax Near '?' When Using Prepared Statement

I am trying to use prepared statements to retrieve data from a SQL DB and display them in an HTML table. When executing the code, I receive the error: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '?' at line 1. Here is my current code:

connection.php

<?php            function openConnection() {          $dbHost = "localhost";          $dbUser = "user";          $dbPass = "pass";          $db = "db";                $conn = new mysqli($dbHost, $dbUser, $dbPass, $db) or die ("Connect failed: %s\n". $conn -> error);                return $conn;      }            function closeConnection($conn){          $conn -> close();      }                  ?>  

index.php

<?php      include('./connection.php');    $uid = $_SESSION['myUID'];    $conn = openConnection();    $sql = "SELECT * FROM my_table WHERE uid=?";  $stmt = $conn->prepare($sql);   $stmt->bind_param('s', $uid);  $stmt->execute();  $stmt->store_result();  $stmt->close();    $result = $conn->query($sql) or die($conn->error);    ?>    <table class="table table-striped">    <thead>      <tr>        <th scope="col" name="tid">Header 1</th>        <th scope="col" name="time">Header 2</th>        <th scope="col" name="last_bump">Header 3</th>        <th scope="col" name="options">Header 4</th>      </tr>    </thead>    <tbody>        <?php          while($row = $result->fetch_assoc()){              echo "<tr>";              echo "<td>" . $row['tid'] . "</td>";              echo "<td>" . $row['time'] . "</td>";              echo "<td>" . updateTime() . "</td>";              echo "<td><button type='submit' class='btn btn-primary btn-sm'>Edit</button>              <button type='submit' class='btn btn-danger btn-sm'>Delete</button></td>";              echo "</tr>";          }        ?>    </tbody>  </table>  

If I remove the prepared statements and replace the ? with an actual value in the SELECT query, it works as intended. What am I doing incorrect here?

https://stackoverflow.com/questions/67052171/error-in-sql-syntax-near-when-using-prepared-statement April 12, 2021 at 11:06AM