View Full Version : Finding out the highest number in an auto-incrementing table
01-21-2012, 10:24 AM
I have a row in a MySQL table called id, which auto-increments.
I was wondering if anyone knows a PHP solution to find out what the highest number in the row is?
I am thinking perhaps execute a MySQL query that will list the highest number, and then echo the result, like $row[id] in PHP?
01-21-2012, 12:06 PM
* Define $server, $username, $password, $database and $table here as follows:
* $server = name of mysql server.
* $username = username for mysql account.
* $password = password for mysql account.
* $database = name of database to use.
* $table = name of table containing the id column.
$conn = mysql_connect($server, $username, $password);
$res = mysql_query("select max(id) from $table;");
$data = mysql_fetch_array($res);
$count = $data;
Of course, you'll need to put some error checking in, but what I've posted above is the basic code to do what you want.
01-21-2012, 12:23 PM
Let me ask, what's your ultimate goal? It looks like you are after a wrong path.
01-21-2012, 01:15 PM
You can also use:
select id from <table> order by id desc limit 1
01-21-2012, 10:47 PM
Do you want the highest number there or do you want the one your script just inserted?
If the latter then you want "SELECT LAST_INSERT_ID()"
That function retrieves the last value actually inserted by the currently running copy of the script and will ignore any higher numbers inserted by someone else since you inserted yours.
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