[PHP] Question on mysql_fetch_object()

[Walter Wojcik]

I am trying to write a script that checks a table for a value in MySQL.  It opens the 
table and queries it fine but if my query returns nothing i have no way of testing to 
see if it returned anything.  I have tried testing for "false" and "" and ! $result in 
a if statement but i don't know what to do.  How do I check to see if i got anything 
or not without getting this:  "Notice: Trying to get property of non-object ". This is 
my most current version of the code:
 

 $id = session_id();
 
 function logOut($session__id)
 {
    
  $link = mysql_connect( "localhost", "shopper", "shopper" );
  
  if ( ! $link )
  {
   die("Couldn't connect to MySQL");
  }  
  
  mysql_select_db( "shopingsystem" ) or die("Couldn't open Datatabase");
  
  $query1 = "select * from userInfo WHERE session_id=\"$session__id\"";
  
  $result = mysql_query( $query1, $link );  // query for username of person with this 
session id
  
  if ( $result ) // Here i test for query failure but it does no good for empty but 
successful results
  {
   if (! $result)  // Here is where i want to test for empty result but it does no 
good!
       // I have tried ($result == false), ($result == "") and (! $result)
       // None do any good they all let an empty result pass.
   {
    print "Query failed for $session__id <br>";
   }
    
   print "Query successful for $session__id <br>";
   
   $temp = mysql_fetch_object( $result );
   
   
   
   $un = $temp->username; // Here is where i get "Notice: Trying to get property of 
non-object" error!
   
   $query2 = "UPDATE userinfo SET session_id='NULL', is_logged_on='F', 
last_logon='NULL' WHERE username='$un'";
   
   $result = mysql_query( $query2, $link ); 
  
   if ( $result )
    print "Logout successful for $un";
    
   session_unset();
   session_destroy();  
  }
  else
   print "Query Failed for $session__id";  
   
  mysql_close( $link );  
 }
Can you help me?


"Knowledge is power, Those who have it must share with those who don't"
                                                                                  
-Walter Wojcik



                
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