Solved

adodb transactions with php. 500 points. PLEASE HELP!

Posted on 2007-04-11
10
742 Views
Last Modified: 2013-12-12
hi experts

has anyone any experience with using adodb transactions? i have three innodb tables that i need to make changes on as a transaction. i read the adodb manual, and have done what they said, which is basically using:

$db->StartTrans();
$db->Execute($sql_1);
$db->Execute($sql_2);
$db->Execute($sql_3);
$db->CompleteTrans();

but whenever i deliberately mess up a sql statement, nothing is rolled back. in fact, it's no different to writting the above code without the starttrans() line. i'm using a peristant connection (PConnect) and have set autorollback just in case, like this:

$db = &NewADOConnection('mysql');
$db->autoRollback = true;
$db->PConnect($server, $userid, $password, $database);

but nothing works. i've done a search on here, and a google, but have found nothing. HELP!
0
Comment
Question by:geordie007
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
  • 2
  • +1
10 Comments
 
LVL 29

Accepted Solution

by:
TeRReF earned 168 total points
ID: 18892302
Check what the Execute method returns when a query fails and use that something like (this example assumes it returns false):

$complete = true;
$db->StartTrans();
$complete = $db->Execute($sql_1);
if ($complete)
  $complete = $db->Execute($sql_2);
if ($complete)
  $db->Execute($sql_3);
if ($complete)
  $db->CompleteTrans();
else
  // perform a rollback
0
 
LVL 8

Assisted Solution

by:netmunky
netmunky earned 166 total points
ID: 18892626
try:
$db->StartTrans();
if( ! $db->HasFailedTrans() && ! $db->Execute( $sql_1 ) ) { $db->FailTrans(); }
if( ! $db->HasFailedTrans() && ! $db->Execute( $sql_2 ) ) { $db->FailTrans(); }
if( ! $db->HasFailedTrans() && ! $db->Execute( $sql_3 ) ) { $db->FailTrans(); }
$db->CompleteTrans();
0
 
LVL 7

Author Comment

by:geordie007
ID: 18892748

thanks guys, but two things:

firstly, aren't both your methods missing the point of what the new 'smart' transactions are supposed to be able to do in adodb? from what the manual suggests, the code that i wrote in my question should work and commit/rollback as necessary, without any error checking. or is the manual stretching the truth a little bit and i'm being a bit naive?

secondly, if my first point is wrong, and actually you do have to do your own error checking, your methods don't suggest a rollback. if anything i would have to create a further three statements, executing each one of the corresponding initial statement failed. surely that can't be right?

0
Will your db performance match your db growth?

In Percona’s white paper “Performance at Scale: Keeping Your Database on Its Toes,” we take a high-level approach to what you need to think about when planning for database scalability.

 
LVL 8

Expert Comment

by:netmunky
ID: 18892928
i have not use adodb myself, but reading further in the manual, it appears you are correct. it *should* be working. (http://phplens.com/lens/adodb/docs-adodb.htm#ex11)

when an execution fails, is it die()ing php at that statement, or continuing on to the completetrans?
0
 
LVL 7

Author Comment

by:geordie007
ID: 18910330

it's completing. so if i'm executing three statements, it carrys out all three statements, regardless if one or more error, and regardless of where that error/s occurs.

in other words, my code may as well be:

// $db->StartTrans();
$db->Execute($sql_1);
$db->Execute($sql_2);
$db->Execute($sql_3);
// $db->CompleteTrans();

0
 
LVL 8

Expert Comment

by:netmunky
ID: 18910838
have you checked what the return value is of StartTrans?
according to comments in the source code, the function returns false if the database (not the table) does not support transactions. under what conditions a database would not support transactions i'm not sure of, but that can be further investigated if needed.
0
 
LVL 5

Assisted Solution

by:rhysp
rhysp earned 166 total points
ID: 19450969
Try this for debugging:

$db->debug = true;
$db->StartTrans();
$db->Execute($sql_1);
$db->Execute($sql_2);
$db->Execute($sql_3);
$db->CompleteTrans();

See what it outputs. Depending on what you are deliberately doing to make it fail it might not actually be failing, just affecting 0 rows.

Also, make sure you are using the mysqli driver. According to the ADOdb docs, you need to use mysqlt as the database driver (mysql with transaction support). If you aren't using the right driver it will ignore the transactional stuff anyway.
0
 
LVL 5

Expert Comment

by:rhysp
ID: 19469217
You could also try mysqli as the driver (instead of mysql or mysqlt) as this already includes transaction support and has the improved functionality for MySQL 4.1+.
0

Featured Post

Webinar: MongoDB® Index Types

Join Percona’s Senior Technical Services Engineer, Adamo Tonete as he presents “MongoDB Index Types, How, When and Where Should They be Used?” on Wednesday, July 12, 2017 at 11:00 am PDT / 2:00 pm EDT (UTC-7).

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article shows the steps required to install WordPress on Azure. Web Apps, Mobile Apps, API Apps, or Functions, in Azure all these run in an App Service plan. WordPress is no exception and requires an App Service Plan and Database to install
This article discusses how to implement server side field validation and display customized error messages to the client.
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.
The viewer will learn how to create a basic form using some HTML5 and PHP for later processing. Set up your basic HTML file. Open your form tag and set the method and action attributes.: (CODE) Set up your first few inputs one for the name and …

724 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question