its used a lot by java. As setting up and closing down connections to the database is relatively expensive, you use a pool manager, when the connection is closed by your code, it gets returned to the pool of open connections and is'nt actually closed. just held open and returned next time you want a connection. So I imagine if you have 20 users on the site at once, then they could all be executing various snippets of sql over 5 connections.
-----Original Message----- From: denonymous [mailto:[EMAIL PROTECTED]] Sent: 02 May 2002 08:27 To: Sean O'Donnell; [EMAIL PROTECTED] Subject: Re: ensuring that I'm getting the correct "last insert ID" Admittedly, I'm no expert. What *is* connection pooling? ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, May 02, 2002 11:21 AM Subject: RE: ensuring that I'm getting the correct "last insert ID" > what happens if you are using connection pooling though? > > > -----Original Message----- > From: denonymous [mailto:[EMAIL PROTECTED]] > Sent: 02 May 2002 08:09 > To: [EMAIL PROTECTED] > Subject: Re: ensuring that I'm getting the correct "last insert ID" > > > From: "Jonnycattt" <[EMAIL PROTECTED]> > > > Hi all, > > I know this has been asked a bunch of times, but i need some clarity (new > > mySQL user). > > I have an app that inserts a new user into one table, then inserts some > user > > preferences into another table. the procedure is as follows: > > 1) insert new user > > 2) query for that user's id using select max(userID) as LastUserID from > .. > > 3) insert into user preferences table using the previous query's > LastUserID. > > To be clear, this last insert adds mutliple rows to a table, not one row. > > > If I were you, I'd use MySQL's LAST_INSERT_ID() function: > http://www.mysql.com/doc/M/i/Miscellaneous_functions.html > > So long as your ID field is AUTO_INCREMENT, this will return the last > auto-generated field in the current handle. > > Something like this: > > INSERT INTO UserTable... (your first user insert) > SELECT LAST_INSERT_ID() FROM UserTable (this will return the userID of the > user you just inserted) > INSERT INTO OtherTables (pass the userID you just got to these queries) > > > You'd mentioned worries that a user could be added while another user was > still being processed, and the result would be the wrong userID being > returned. LAST_INSERT_ID() is handle-based, though, so there should be no > worries with that -- the sessions will be kept separate. > > Hope this helps! > > > -- > denonymous . : . : . AIM: denonymous > http://www.coldcircuit.net ' : ' : ' http://24.91.199.33 > > "According to one of our readers, the new MacOS X contains another > Satanic holdover from the 'BSD Unix' OS mentioned above; to open up > certain locked files one has to run a program much like the DOS > prompt in Microsoft Windows and type in a secret code: 'chmod 666'." > > > > --------------------------------------------------------------------- > Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail > <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
