Ashley Sheridan wrote: > On Wed, 2009-02-25 at 14:10 -0800, Gary W. Smith wrote: >> Not sure that this is the problem BUT you should probably qualify the >> name of the variable such that "SELECT MAX(id) AS id FROM book". But >> you don't want "max(id) as id" but rather "max(id) + 1 as id". With >> that you can then just return the final value. Also, if you don't >> want to alias the value (or whatever it's called) you should use >> $row[0] to get it by ordinal posistion. >> >> As for now wanting to use autoincrement, you can run into a race >> condition where two people are inserting at the same time, thus >> having the same generated id. >> >> Hope that helps. >> >> >> ________________________________ >> >> From: PJ [mailto:af.gourmet@xxxxxxxxxxxx] >> Sent: Wed 2/25/2009 2:01 PM >> To: MySql; php-general@xxxxxxxxxxxxx >> Subject: non-auto increment question >> >> >> >> I want to insert a new table entry 1 number higher than the highest in >> the field (id). I cannot use auto-increment. >> And I want to show the value of the field to be added in an input field >> on the web page: >> if (isset($_REQUEST["AddNewBooksRequest"])) { >> $SQL = "SELECT MAX(id) FROM book"; >> $result = mysql_query($sql, $db); >> $bookCount = mysql_num_rows($result); >> for ($i=0; $i < $bookCount; $i++) { >> $row = mysql_fetch_array($result); >> $idIN = $row["id"]+1; Actually, I am wondering how to get rid of some of the code here as it seems a little bloated.... How do I get rid of the row counting - since there can never be more than one row returned with this query. >> } >> $idIN = $_POST["idIN"]; >> $titleIN = $_POST["titleIN"]; >> >> ...snip... >> >> <td colspan="2"> >> <? >> echo "<input type='text' name='titleIN' value='$idIN' disabled >> size='2'>"; >> ?> >> </td> >> >> What am I doing wrong? (The query works and returns the right nr. but >> what do I have to do to add 1 to that number and then display it in the >> on page and post it to the table? >> >> -- >> >> Phil Jourdan --- pj@xxxxxxxxxxxxx >> http://www.ptahhotep.com <http://www.ptahhotep.com/> >> http://www.chiccantine.com <http://www.chiccantine.com/> >> >> >> -- >> MySQL General Mailing List >> For list archives: http://lists.mysql.com/mysql >> To unsubscribe: http://lists.mysql.com/mysql?unsub=gary@xxxxxxxxxxxxxxx >> >> >> > Yeah, this sort of situation is really what auto increment is for. If > you get two people visiting the page with this code on at the same time > then you'll screw up your database. > > > Ash > www.ashleysheridan.co.uk > > Being rather new to all this, I understood from the MySql manual that the auto_increment is to b e used immediately after an insertion not intermittently. My application is for administrators (the site owner & designates) to update the database from and administration directory, accessed by user/password login... so there's really very little possibility of 2 people accessing at the same time. By using MAX + 1 I keep the id number in the $idIn and can reuse it in other INSERTS -- Phil Jourdan --- pj@xxxxxxxxxxxxx http://www.ptahhotep.com http://www.chiccantine.com -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
