PHP get last auto increment id (read all topics but cant get my code to work)

Question

I am trying to update a value into my table with the last ID, but I can not get mysql_insert_id() working. Can someone help me (I am a beginner with PHP). Thanks in advance!

This is a piece of my code, I know that mysql is outdated but I am doing this as a school project:

$tijd = date("H:i:s");
$userid = mysql_insert_id();        
$query = "UPDATE tijden SET tijduit = '$tijd' WHERE id = '$userid'";
$resultaat = mysql_query($query);    
unset($_SESSION['inchecken']);

As the title says: I read all the other topics but I can not get my code to work, that's why I sent my own code. — stacksjouwer, Jun 12 '15 at 14:26

score -1 · Answer 1 · answered Jun 11 '15 at 22:57

$tijd = date("H:i:s");
$userid = mysql_insert_id();

You cannot get a mysql_insert_id() without doing an INSERT query. If you are trying to retrieve the last record do the following query:

SELECT id FROM tijden ORDER BY id DESC LIMIT 1

From there get the last ID and use this variable to update the record below.

$query = "UPDATE tijden SET tijduit = '$tijd' WHERE id = '$userid'";
$resultaat = mysql_query($query);

You do not necessarily need to separate the $query variable from the function. Simplify by doing:

$resultaat = mysql_query("UPDATE tijden SET tijduit='$tijd' WHERE id='$userid'");

Thanks! I am going to try this! – stacksjouwer Jun 11 '15 at 22:59 — stacksjouwer, Jun 11 '15 at 22:59

PHP get last auto increment id (read all topics but cant get my code to work)

1 Answers1