mySQL query - still returns error mysql_fetch_array [duplicate]

Question

Possible Duplicate:
mySQL query multiple - returns error mysql_fetch_array

I have 2 database tables (for a booking system) with the following structures:

quartos:

id_quarto.
tipo_quarto.
vista_quarto.

reservas:

id_reserva.
n_cliente.
id_quarto.
check_in.
check_out.

I want the query to return the quartos (rooms) available (with the fields id_quarto / tipo_quarto / vista_quarto from it) which arent already being booked on reservas (reservations) so i write the following query (also picking information from a previous form):

NOTE: At this time i am not considering the check_in and check_out dates factor... this is only a test and therefore i will add the conditions to check it too, but if anyone has some ideas for those conditions i would be grateful. :D

// Connect to database server
mysql_connect("localhost", "root") or die (mysql_error ());

// Select database
mysql_select_db("teste") or die(mysql_error());

// Get data from the database

    $strSQL = "SELECT id_quarto,tipo_quarto,vista_quarto ".
              " FROM quartos,reservas ".
              " WHERE quartos.id_quarto!=reservas.id_quarto ".
              " AND quartos.tipo_quarto='". mysql_real_escape_string($_POST['tipo_quarto']) ."' ".
              " AND quartos.vista_quarto='". mysql_real_escape_string($_POST['vista_quarto']) ."'";
$rs = mysql_query($strSQL);


    // Loop the recordset $rs
        // Each row will be made into an array ($row) using mysql_fetch_array
        while($row = mysql_fetch_array($rs)) {

    ?>
    <table border="1">
        <tr align="left">
        <td width="75"><?php echo $row['id_quarto']; ?></td>
        <td width="75"><?php echo $row['vista_quarto']; ?></td>
        <td width="75"><?php echo $row['tipo_quarto']; ?></td></tr>
      </table>
     <?php 
     }

       // Close the database connection
    //  mysql_close(); ?>

But when I do this it returns an error on Line X, which is the line when i loop the recordset saying that "mysql_fetch_array() expects parameter 1 to be resource, boolean".

Why is this and what can i do to prevent it? how do i write the correct code?

Also, i wanted the results to be featured as a Select (List/Menu) form item so that user the could only choose the valid results. Any idea how to incorporate the results from the recordset with this feature?

Answer 1

You missed

$rs=mysql_query($strSQL)

Ofcourse immediately before

// Loop the recordset $rs

Answer 2

Strictly you should be saying:

if ($rs=mysql_query($strSQL)) {

// Proceed with while loop

} else echo mysql_error();

The query might be raising an error???