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how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 7:30 am
by monsta-toast
hi what is the correct code for selecting the last row id in mysql table?

Code: Select all

$query="SELECT max(ID) FROM inventory ";
i tried this but it doesn't work :banghead:

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 7:59 am
by Ziq
Do you have some errors?

Why are you using this query? If you want to insert data into database you should use the auto_increment attribute. MySQL Manual

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 8:10 am
by monsta-toast
no i want to select the last id from the database so i can use the id as a unique file name for images.

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 9:42 am
by John Cartwright
monsta-toast wrote:hi what is the correct code for selecting the last row id in mysql table?

Code: Select all

$query="SELECT max(ID) FROM inventory ";
i tried this but it doesn't work :banghead:
This will give you the highest ordered ID, so yes it does work. Please post the relevant code and errors describing why this doesn't work.

If you are inserting a row in the database and simply want it's ID back, you can use mysql_insert_id().

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 10:12 am
by monsta-toast
John Cartwright wrote:
monsta-toast wrote:hi what is the correct code for selecting the last row id in mysql table?

Code: Select all

$query="SELECT max(ID) FROM inventory ";
i tried this but it doesn't work :banghead:
This will give you the highest ordered ID, so yes it does work. Please post the relevant code and errors describing why this doesn't work.

If you are inserting a row in the database and simply want it's ID back, you can use mysql_insert_id().
This function returns 0 if the previous operation does not generate an AUTO_INCREMENT ID, or FALSE on MySQL connection failure. so how do i get the last id and add 1 to it? then use the id created as a file name?

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 11:08 am
by monsta-toast
anyone? :banghead:

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 11:18 am
by John Cartwright
Are you asking how to execute the query?

Code: Select all

$query="SELECT max(ID) AS `maxid` FROM inventory ";
$result = mysql_query($query) or die(mysql_error());
$row = mysql_fetch_assoc($result);
echo $row['maxid'];
Also, please do not bump your post within 24 hours of your last post.

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 11:26 am
by monsta-toast
Thanks A million!

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 12:24 pm
by abel

Code: Select all

$query="SELECT max(ID) FROM inventory limit 0,1";
right?

Re: how do you select the last id in my sql table?

Posted: Sun Feb 08, 2009 12:50 pm
by Kastor

Code: Select all

SELECT LAST_INSERT_ID()