MySql select highest number

darko886

Hello, I was wondering how can I perform a MySql query to select the highest number under the "number" column? The number column is an auto_increment...

alimadzi

darko886 wrote:
Hello, I was wondering how can I perform a MySql query to select the highest number under the "number" column? The number column is an auto_increment...

SELECT number FROM table_name ORDER BY number DESC LIMIT 1

darko886

Thanks, but now it gives me an error.

<?php 

require_once("config.php") // include your mysql connection file

$result = mysql_query("SELECT number FROM status ORDER BY number DESC LIMIT 1");
while($row = mysql_fetch_array($result))
  {
$number = $row['number'];
echo "Paiement réussi! Vous numéro de commande est $number";

}



?>

That is my code, this is the error:

Parse error: parse error, unexpected T_VARIABLE in C:\Inetpub\vhosts\ivioodgame-fr.com\httpdocs\test.php on line 5

darko886

nevermind, i wasnt paying attention, stupid mistake! forgot to ; the 3rd line

alimadzi

Since you're only selecting one row, you can make this a one-liner instead of using a while() loop...

$row = mysql_fetch_assoc( mysql_query( "SELECT number FROM status ORDER BY number DESC LIMIT 1" ) );
$number = $row['number'];

Just a thought...

laserlight

Talking about one-liners, since you are only retrieving one column one could even write:

$number = mysql_result(mysql_query("SELECT number FROM status ORDER BY number DESC LIMIT 1"), 0);

Though I prefer checking the return value of mysql_query() before going on to use mysql_fetch_assoc() or mysql_result().

NogDog

I don't know if this processes any faster, slower, or the same as the ORDER BY/LIMIT method, but you could do the following shorter query, instead:

SELECT MAX(`number`) FROM `status`

alimadzi

Good call. The two queries should be similar in processing time with NogDog's being a bit faster. The question to ask yourself is whether or not you need any other information from the row with the highest 'number'. If you don't, go ahead and use NogDog's query. If you do, then use the original ORDER BY / LIMIT query and add the other columns to the SELECT.