Question

Possible Duplicate:
mysql_fetch_array() expects parameter 1 to be resource, boolean given in select

So I am trying to check if the following query returns any result or not

  $numUsersSameRatingQuery="SELECT * `user ratings` WHERE  category='$category' AND categoryId='$categoryId' AND  `userAromaRating`>0 ";

  $result=mysql_query($numUsersSameRatingQuery);

   $numResults=mysql_num_rows($result);

  if($numResults==0)
  {
   // do the INSERT INTO
  }
  else
  {
   //do the UPDATE SET
  }

However, the above returns the following error and the if($numResults) is executed anyway each time. In other words, I can never get the else block to run.

Here is the error

 Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\boozeDb\profileThis.php on line 141

Helps are appreciated.

Answer 1

You could use is_resource to make sure that it’s a resource. You could alternatively use an if statement to make sure that FALSE wasn’t returned.

To display the error, use mysql_error.

Example:

<?php

// From https://www.php.net/manual/en/function.mysql-query.php

$result = mysql_query('SELECT * WHERE 1=1');
if (!$result) {
    trigger_error('Invalid query: ' . mysql_error());
}