How to display error when no rows available?

PHP
1

Hey all

I have a MySQL Database with a coupe of rows and a page setup to display the data in mysql. To do so, I go to www.site.com/example.php?id=2 and it iwll bring me the row 2 of data from the database.

However, is it possible if someone enters www.site.com/example.php?id=100, it will bring out an error message if there is no id 100?

Thanks

2

It is possible. Check if the SQL result is empty, that is, check if no rows were returned. Usually, if the result is empty it gives false, so an if-else might do it.

3

use


	if(mysql_numrows($res) == '0'){
	echo 'no results';
	}
	else{
// do something
        }
4

That would work under the assumption you are using mysql function syntax (which is discouraged), but I’d rather see you not put the 0 in quotes and use ===

if (mysql_num_rows($res) === 0)
{
  // no results, return your error
}
else
{
  // put what you have currently here
}

If you are using mysqli, you can do one of the following

if (mysqli_stmt_num_rows($res) === 0)
{
  // no results, return your error
}
else
{
  // put what you have currently here
}

Or

// assumption you have a $mysqliObject
$stmt = $mysqli->prepare($query)
$stmt->execute();
if ($stmt->num_rows === 0)
{
  // no results, return your error
}
else
{
  // put what you have currently here
}

Then there is PDO

$stmt = $dbh->prepare('your query here');
$stmt->execute();
if ($stmt->rowCount() === 0)
{
  // no results, return your error
}
else
{
  // put what you have currently here
}
5

Thanks you all, and also cpradio because I’m using PDO and helped me on this issue (: