Opinion on database search..

[Scooby08]

I'm just looking for an opinion on a recommended way to search a database for a specific value..

 

Would it be one of the following or perhaps there is a better approach??

 

<?php
$count = mysql_result(mysql_query("SELECT count(*) FROM bank_routing_numbers WHERE blacklist='091000019'"),0);
if ($count > 0) {
// exists
} else {
// doesnt exist
}
?>

 

or

 

<?php 
$num_rows = mysql_num_rows(mysql_query("SELECT blacklist FROM bank_routing_numbers WHERE blacklist='091000019'"));
if ($num_rows > 0) {
// exists
} else {
// doesnt exist
}
?>

[Illusion]

See it for yourself by run the queries using EXPLAIN from any sql client.

[fenway]

There could be thousands of matching rows -- don't get data just to throw it out.