Checking for 0 results in MySQL

[pthurmond]

For my username signup script I need to check to see if the username exists. To do that I just want to run a query on the username table that tries to match the username input from the user. The basic concept is if $results > 0 then the username is taken. My concern is that it will always give errors with zero results.

Currently I use the following to pull results:
$result = mysql_query($idQuery) or die('Query failed: ' . mysql_error());

If I change it to the following will I be able to run the query error free when getting the results:
$result = mysql_query($idQuery);


Thanks,
Patrick

[alpine]

Use mysql_num_rows() to check this, the query will always return 1 (true) if it is a valid query - regardless of what is found or not based on the query:

[code]
<?php

$query = mysql_query("select what from table") or die(mysql_error());

if(mysql_num_rows($query) > 0)
{
  // returned 1 or more results
}

?>
[/code]

[The Little Guy]

[code]<?php

$query = mysql_query("SELECT * FROM table") or die(mysql_error());
$row = mysql_fetch_array($query);

if(!$row)
{
    // returned no results
}else{
    //returned 1 or more results
}

?>[/code]