Converting MySQLI to MySQL functions

[teen342]

Hey there I seem to have been having problems getting this peice of code to work on a MySQL 4.x server but the code given was wrote for a MySQL 5.x server.

 

P.S. I have commented out the mysqli version which came with the example given.

[pre]

41 // Define the read_session() function:

42 // This function takes one argument: the session ID.

43 // This function retrieves the session data.

44 function read_session($sid) {

45

46 global $sdbc;

47

48 // Query the database.

49 #$q = sprintf('SELECT data FROM session WHERE id="%s"', mysqli_real_escape_string($sdbc, $sid) );

50 #$r = mysqli_query($sdbc, $q);

51 $q = sprintf('SELECT data FROM session WHERE id="%s"', mysql_real_escape_string($sid, $sdbc) );

52 $r = @mysql_query($q);

53

54 // Retrieve the results.

55 #if(mysqli_num_rows($r) == 1) {

56 if(mysql_num_rows($r) == 1) {

57

58 #list($data) = mysqli_fetch_array($r, MYSQLI_NUM);

59 list($data) = mysql_fetch_array($r, MYSQL_NUM);

60

61 // Returns the data:

62 return $data;

63

64 } else {

65

66 return '';

67

68 }

69

70 }

[/pre]

The error I am getting is

 

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/users/uks61947/html/teen342online.me.uk/projects/php5adv/ch03/includes/db_sessions.inc.php on line 56

 

[uniflare]

an invalid result resource usually means the query returned false or errored.

 

Change line 52 to: $r = @mysql_query($q) or die("MYSQL QUERY ERROR: <br>".mysql_error()."<hr>");

 

See if mysql is saying anything, could be a problem with your query.

Unless your query result is empty, try the exact same query in phpmyadmin if u can.

[wildteen88]

The problem is you're using both mysqli_* and mysql_* functions. You cannot use both function types together they are incompatible. You'll have to convert all mysqli_* functions to the old mysql_* functions if you dont want to use mysqli based functions.

 

However mysqli_* functions are compatible with MySQL4.1.3 or above according to php.net. Your mysql queries are most probably the issue and not the code.

[teen342]

Have looked into it and found that the resource in question was reciving a false response due to a little boo boo in the SQL!

 

wildteen88, thanx but if you look closer you will see that all mysqli_ functions are commented out so is not that.

 

Heres the corrected code:

[pre]53 // Define the read_session() function:

54 // This function takes one argument: the session ID.

55 // This function retrieves the session data.

56 function read_session($sid) {

57

58 global $sdbc;

59

60 // Query the database.

61 #$q = sprintf('SELECT data FROM session WHERE id="%s"', mysqli_real_escape_string($sdbc, $sid) );

62 #$r = mysqli_query($sdbc, $q);

63 $q = sprintf('SELECT data FROM sessions WHERE id="%s"', mysql_real_escape_string($sid, $sdbc) );

64 $r = mysql_query($q);

65

66 // Retrieve the results.

67 #if(mysqli_num_rows($r) == 1) {

68 if(mysql_num_rows($r) == 1) {

69

70 #list($data) = mysqli_fetch_array($r, MYSQLI_NUM);

71 list($data) = mysql_fetch_array($r, MYSQL_NUM);

72

73 // Returns the data:

74 return $data;

75

76 } else {

77

78 return '';

79

80 }

81

82 }

[/pre]

[wildteen88]

Change line 64 to:

$r = mysql_query($q) or die('Query error: ' . mysql_error() . '<pre>' . $q . '</pre>');

There is most probably a problem with your query.