PHP MySQL 5最小化查询

Question

$query = mysql_query("SELECT `id`, `username` FROM `users` WHERE `username` = 'admin' LIMIT 1");
if (mysql_num_rows($query))
{
    $row = mysql_fetch_array($query);
    $userid = $row['id'];
}

I need to get userid so fast . How I can minify this code? I very often use related queries. Thank you!

Answer 1

You query is almost nothing can do of minimizing except you don't need to get the username field which is already know in your where clause. And mysql_fectch_assoc() return false if there is no record, so you do not need to use mysql_num_rows().

$query = mysql_query("SELECT `id` FROM `users` WHERE `username` = 'admin' LIMIT 1");
$row = mysql_fetch_assoc($query);
if ($row) {
     $userid = $row['id'];
}