mysql_num_row

Beffic

So I am trying to make a query that doesn't have to be true but if it is them it will send a non-mysql related error. but I keep getting this error.

Fatal error: Call to undefined function mysql_num_row() in /home/riseofim/public_html/riseofimmortals.com/inventory.php on line 48

Crime in progress:

<?php
$CheckClass1=mysql_query("SELECT * FROM Items WHERE Owner='$User[ID]', Class='$Equipping[Class]', Equipped='Yes'");
 $CheckClass=mysql_num_row($CheckClass1);

if($CheckClass>=1){
  print"You already have a(n) ".$Equipping['Class']." equipped!";
 }
?>

What is wrong!?!?!?

Krik

Heres a case of if you had looked in the manual you would have found your answer. Its [man]mysql_num_rows[/man]

Note the error say that mysql_num_row is undefined. Or in other words it doesn't exist.

Beffic

Okay, that worked thanks. But now I get:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result

Could this have something to do with the commas in the where statement?

nevvermind

<?php
$query = mysql_query("SELECT * FROM Items WHERE Owner='{$User['ID']}', Class='{$Equipping['Class']}', Equipped='Yes'");

$rows = mysql_num_row($query);

if ($rows > 0) {

  print "You already have ".$Equipping['Class']." equipped!";

}
?>

$User[ID] will not parse in your syntax. Use { }.

Your query was incorrect, thus your $CheckClass1 was not a result, hence (uf!) $CheckClass was throwing an exception. (you can see how an erroneous query can have a domino effect).

Also, apply some standard naming while at it and make a habit of naming varibles like this: User['ID'].

shamly

mysql_query() returns a resource on success, or FALSE on error.
You can check if the return value is valid by using an if condition as follows

if ($query) 
{
  $rows = mysql_num_rows($query);

  if ($rows > 0) 
  {
      print "You already have ".$Equipping['Class']." equipped!";

  } 

}

This will ensure that if your SQL query is invalid, mysql_num_rows will not get executed.

PradeepKr

I think it should be
if ($query !== false)

if $query is zero then it would not enter into the if block.

bradgrafelman

PradeepKr wrote:
if $query is zero then it would not enter into the if block.

And why would $query ever be zero?

PradeepKr

hmmm ... don't know if a resultset resource can ever be 0 or not. But on failure it returns false and to strictly compare the context I used that.