Auto increment

Anon

I have a table with a primary key (column is called mid) which auto increments.

How do I find the last mid. I thought I could use mysql_num_row but if something is deleted, then:

mysql_num_row != highest mid

Anyone tell me the easiest way to get the highest mid?
I looked in the php manual and I didn't see anything that might help me out.

Thanks,
Marco

kparker

I looked in the php manual and I didn't see anything...

That's odd, it should be there. The function you're looking for is called 'mysql_insert_id():

http://www.php.net/manual/en/function.mysql-insert-id.php

Anon

Actually, what i'm looking for is suppose i've got the following in my table.

mid name
2 John Doe
3 Puff Daddy
4 Tito Jackson

Now, I don't want to get the id of the last insert. I want to query the last mid on a static table. Nothing is going into it on this particular page.

So, if I did a mysql_num_rows, i'd get 3 whereas the mid I want is 4.

Thanks for your suggestion though. Any other ideas?

Marco

miyake

I found the same problem...if you delete say 1 out of 1-4, the next autoincrement will be 5, so you're left with an empty hole. Any suggestions other than filling the hole manually?

kparker

For that, just say:

select max(mid) from table;

Anon

I tried that and I get a empty result.

Below is my coding:
$myquery = "SELECT max(mid) FROM mboard";
$myresult = mysql_query($myquery);
if(!$myresult)
print "ERROR: ".mysql_error();
$row = mysql_fetch_object($myresult);
print "$row->mid is result";

miyake

use mysql_fetch_array and it'll return the row in an array...

$sql = "SELECT MAX(mid) FROM mboard";
$res = mysql_query($sql);
$row = mysql_fetch_array($res);

if ($res) echo $row[0];