How to select data

Method	Description
query($select_statement)	Executes the specified SELECT statement and returns a mysqli object for the result set. If no re-sult set is returned, this method returns a FALSE value.
real_escape_string($string)	Escapes special characters in the specified string and returns the new string.
escape_string($string)	Same as the real_escape_string method.

Property/Method	Description
num_rows	The number of rows in the result set.
fetch_assoc()	Returns the result set as an associative array.

      // Escape the parameters
      $category_id_esc = $db->escape_string($category_id); 
       
      // Execute the statement - manually add single quotes around parameters 
      $query = "SELECT * FROM products WHERE categoryID = '$category_id_esc'";
      $result = $db->query($query); 
       
      // Check the result set 
      if ($result == false) { 
        $error_message = $db->error; 
        echo("An error occurred: $error_message");
        exit;
      } 
      
      // Get the number of rows in the result set 
      $row_count = $result->num_rows;
      

      <?php 
      for ($i = 0; $i < $row_count; $i++) : 
        $product = $result->fetch_assoc(); 
      ?>
      <tr>
        <td><?php echo $product['productID']; ?></td>
        <td><?php echo $product['categoryID']; ?></td>
        <td><?php echo $product['productName']; ?></td>
        <td><?php echo $product['productCode']; ?></td>
        <td><?php echo $product['listPrice']; ?></td>
      </tr>
      

       // close the result set
       $result->free();
       
       // close the db connection
       $db->close();