mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to be resource

Question

I am trying to select data from a MySQL table, but I get one of the following error messages:

mysql_fetch_array() expects parameter 1 to be resource,

Answer 1

You can also check wether $result is failing like so, before executing the fetch array

$username = $_POST['username'];
$password = $_POST['password'];
$result = mysql_query('SELECT * FROM Users WHERE UserName LIKE $username');
if(!$result)
{
     echo "error executing query: "+mysql_error(); 
}else{
       while($row = mysql_fetch_array($result))
       {
         echo $row['FirstName'];
       }
}