RE: [PEAR] Trying to loop through MDB rowset - proposed solution

There's a small bug in there. IsDone() should read as follows: function IsDone($freeResult = true) { if( $this->current > $this->num_rows -1) { if( $freeResult) { mysql_free_result($this->rs); } return true; } return false; } Note: the line: if( $this->current > $this->num_rows -1) now has -1 at the end. Matt Friedman Web Applications Developer www.SpryNewMedia.com Phone: 416 992 5482 Email: matt@SpryNewMedia.com > -----Original Message----- > From: Matt Friedman [mailto:matt@sprynewmedia.com] > Sent: Saturday November 9, 2002 12:34 PM > To: 'smith@dybnet.de'; 'pear-dev@lists.php.net' > Subject: RE: [PEAR] Trying to loop through MDB rowset - proposed solution > > Hi Lucas, > > As I said I wanted to come up with a way to loop through record sets > without putting the set into a php array first. MDB doesn't seem to > provide methods that allow for this. > > I'm sending a rough implementation of an "iterator" class and its > associated factory method class for your consideration. Since the MDB > query method returns a resource id which points to a result set, we don't > have to rely on MDB to loop through the set. We can pass the result id to > another class which can then be responsible for providing each item in the > list. This hides the database implementation and allows for all sorts of > iteration classes to be written that could make use of cursors etc... > Looping backwards through the set is one example and so on... > > A couple of other advantages: you can choose whether or not to free the > result at the end of the loop (see IsDone()) and if you don't free it, you > can re-use the iterator and loop through the same set again. The default > is to free the set. Also, this solution doesn't require changing MDB at > all. > > Anyway, I think my code is fairly self explanatory if not complete. There > needs to be lots more error checking and PEARifying if you want to use it; > but I wanted to contribute the idea. If you have any questions please let > me know. > > I hope this turns out to be helpful and useful. :) > > Matt Friedman > matt@SpryNewMedia.com > > > > > -----Original Message----- > > From: Matt Friedman [mailto:matt@sprynewmedia.com] > > Sent: Thursday November 7, 2002 4:58 PM > > To: smith@dybnet.de; pear-general@lists.php.net > > Subject: RE: [PEAR] Trying to loop through MDB rowset - > > > > Hi again Lukas, > > > > I've been thinking (ruminating) about this and have a solution (in my > > mind) about a way to satisfy this problem without having to touch MDB at > > all. What I don't like about the current way is that MDB loops through > > the results and then I have to loop through the results again to handle > > the data. Makes more sense to me to just loop once. > > > > I'll work on something and submit something to you - you can let me know > > if it looks reasonable. Give me a day or so. > > > > Matt Friedman > > Web Applications Developer > > www.SpryNewMedia.com > > Phone: 416 992 5482 > > Email: matt@SpryNewMedia.com > > > > > > > > > -----Original Message----- > > > From: Lukas Smith [mailto:smith@dybnet.de] > > > Sent: Thursday November 7, 2002 2:42 PM > > > To: 'Matt Friedman'; pear-general@lists.php.net > > > Subject: RE: [PEAR] Trying to loop through MDB rowset - > > > > > > > From: Matt Friedman [mailto:matt@sprynewmedia.com] > > > > Sent: Thursday, November 07, 2002 8:32 PM > > > > To: smith@dybnet.de; pear-general@lists.php.net > > > > Subject: RE: [PEAR] Trying to loop through MDB rowset - > > > > > > > > Thanks very much Lucas. > > > > > > > > Is loading up a new array with the whole result set ok (as in > > > queryAll)? > > > > I had actually thought that using the Resource Id instead of filling > > a > > > > result set object/array was more efficient. The impression I have is > > > > that using a result id uses less memory. What about large result > > sets? > > > > This may not be a big issue - I'm just throwing it out there. But > > > that's > > > > actually why I was trying to avoid using queryAll if I could. > > > > > > > > What about the ability to _not_ free the result so that you can > > > continue > > > > to loop through using the resource id when you use fetchRow etc...? > > > (via > > > > some flag or something?) > > > > > > > > Anyway, thanks again :) > > > > > > > > > > well hmmm ... > > > I ported this behavior from DB's get+() methods. > > > Recently there was the addition of autofree (automatically free a > > result > > > set when the end of the result set is reached). So maybe I shoud > > > re-examine this. Adding another flag is probably not a good idea > > because > > > most methods in MDB have so many parameters already due to the > > datatype > > > abstraction. > > > > > > Fetching everything at once will be faster I am quite sure as you have > > > less function calls. Then again you might be right that is uses more > > > memory. > > > > > > Regards, > > > Lukas > > > > > > > > > -- > > > PEAR General Mailing List (http://pear.php.net/) > > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > > -- > > PEAR General Mailing List (http://pear.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php