Call to a member function fetch_assoc() on boolean in <path>

Question

I'm getting the above error when running the below code to display bookings made from a database.

<?php
        
        $servername = "localhost";
        $username = "*********";
        $password = "********";
        $dbname = "thelibr1_fyp";


        // Create connection
        $conn = new mysqli($servername, $username, $password, $dbname);
        // Check connection
        if ($conn->connect_error) {
            die("Connection failed: " . $conn->connect_error);
        } 
        
        $sql = "SELECT id, tablename, numseats, person FROM confirms";
        $result = $conn->query($sql);
        ?>
                        
        <table id="Confirms" border ="2" style="length:900px;width:350px;">
              <thead>
                <tr style= "background-color: #A4A4A4;">
                  <td>Booking ID:</td>
                  <td>Table No.:</td>
                  <td>No. of Seats:</td>
                  <td>Person:</td>
                </tr>
              </thead>
            <tbody>
                <?php
                  while(($row = $result->fetch_assoc()) !== null){
                    echo
                    "<tr>
                      <td>{$row['id']}</td>
                      <td>{$row['tablename']}</td>
                      <td>{$row['numseats']}</td>
                      <td>{$row['person']}</td>
                    </tr>\n";
                  }
                ?>
            </tbody>
        </table>

I only started to receive the error when i started hosting it live. It works fine on my personal computer, the databse connection works fine also.

Answer 1

The query method can return false instead of a result set in case there is an error. That is why you get the error on the fetch_assoc method call, which obviously does not exist when $result is false.

This means you have an error in your SELECT statement. To get that error displayed, do this:

 $result = $conn->query($sql) or die($conn->error);

Most probably you have a wrong spelling for the table name or a column name. Maybe when moving to the host you did not create that table correctly, and made a spelling mistake there.

You should in fact see the same error when executing the same query via phpAdmin.

Also, replace this line:

while(($row = $result->fetch_assoc()) !== null){

with just:

while($row = $result->fetch_assoc()) {

You could also add this for debugging:

echo "number of rows: " . $result->num_rows;