Problem with Max() function

Anon

Hi,

I'm having some trouble with MySQL's max() function inside php. The results I'm getting in the MySQL shell are much diffrent from the results I'm getting in PHP.

For example,

mysql_connect ($database[host], $database[user], $database[password]);
mysql_select_db ($database[database]);
$testing = mysql_query("SELECT MAX(id) FROM sampledatabase");

produces 2. Now if I run this command inside the MySQL shell as -

SELECT MAX(id) FROM sampledatabase;

it produces 5, which is the right number of records. I've looked in a few books ( mostly inside mSQL and MySQL by O'reilly ) and I haven't found anything about this. Any idea what's going on, or am I just doing something really basic wrong.

Thanks,

-Alex Augot
Teradyne, Inc

Anon

Now if I run this command inside the MySQL shell as -

SELECT MAX(id) FROM sampledatabase;

it produces 5, which is the right number of records.

MAX() does not produce a count of rows, it returns the highest value found in the column. COUNT() returns the count. Which of these is the thing you're actually after?

Also, are you sure you are loggin in to the same database interactively as you are from within php?

Anon

Hi,

Since what I'm looking for is an auto incrementing primary key (id), it should return 5, like it does in PHP.

As for the database being the same, I'm sure it is. I double checked that before I posted.

As for the count, I'll try that and see if I get diffrent results.

-Alex Augot
Teradyne, Inc

Anon

How are you displaying the result? You just say "produces 2". An educated guess is that you are displaying the value of $testing, which is NOT the return value of the query but an index to the result set. You'll have to use one of the mysql_fetch_*() or mysql_result() functions to actually get the data returned by the query.