@nikosdion Can you try testing this please? I can't reproduce it 100% of the time so I'm not sure if this solves it or not - it definitely seems to solve the weblinks/general component install issue though

@wilsonge shouldn't also be needed to set the sql_mode in pdomysql to an empty value to match with mysql and mysqli db drivers current sql_mode?

$this->connection->query("SET @@SESSION.sql_mode = '';");

Will remove all warnings and is not a solution itself (since IMHO it should use strict mode in all drivers) but, for now, the 3 mysql db drivers (mysql, mysqli and pdomysql) should have the same sql_mode for consistency.

See:

• Mysql: https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/database/driver/mysql.php#L94-L95
• Mysqli: https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/database/driver/mysqli.php#L186-L187

Or the idea is to had strict sql mode in all mysql db drivers in 3.5.0+?

@wilsonge I just tested with the modified weblinks package. The errors I had before have disappeared now, but now I run into following:

Warning
SQLSTATE[HY000]: General error: 1364 Field 'system_data' doesn't have a default value
Package Install: There was an error installing an extension: mod_weblinks.zip
Error
Error installing package

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_{This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/9461.}

@wilsonge In addition I still have the problem I mentioned yesterday on Skype:

The extensions update status is shown as unknown on the control panel.

When I go to "Extensions -> Manage -> Update" and click the "Find Updates" button, it ends with this sql error:

SQLSTATE[HY000]: General error: 1364 Field 'data' doesn't have a default value

Shall I open a new issue for that? Or will you handle it with this PR here, too?

I can't replicate that :( Like the PR adds a line to deal with exactly that issue for modules: https://github.com/joomla/joomla-cms/pull/9461/files#diff-6544c81f9f6cf3dad62bf0e394ed9792R377 - are you sure it's applied properly :/

Ahhh just as you say it: No, you PR was not applied with latest changes (shame). I'll do and test again soon.

@wilsonge Ok, tested with success the stuff from issues mentioned here.

But again my question: What to do with the error on "Find Updates"? Wanna handle this with this PR here?

In this case I wait with marking test result.

Or with another issue?

In this case I mark test result positive here.

But I would prefer you to handle the new issue then for this "Find Updates" problem, because you now know better than me where to look and can immediately make a PR with the issue maybe.

It just needs a change here https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/updater/updater.php#L182 to ensure that the update property is set - but I can't work out what data the column is supposed to contain from here - will look up on it tonight

@wilsonge "will look up on it tonight" means in a new PR/issue so I shall mark test result of this one here with success, or means do this thing also with this PR so I shall wait?

I applied the patch to staging but it doesn't fix the issue for me. I keep getting the same error :(

@wilsonge @nikosdion i can't reproduce the problem, to check if this works. For what i understand, the issue is:

HY000 SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll().
Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.

Adding a PDO::MYSQL_ATTR_USE_BUFFERED_QUERY flag to the beginning of the pdomysql.php connect method so it can be used on PDO connect probably works.

    public function connect()
    {
        $this->options['driverOptions'][PDO::MYSQL_ATTR_USE_BUFFERED_QUERY] = true;
        // [...]
    }

In https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/database/driver/pdomysql.php#L103-L104

UPDATE: Has able to reproduce the problem and the fix i proposed doesn't work.
To reproduce:
1. Install latest staging (with mysqli driver)
2. Install Akeeba Backup 4.5.4 or lower
3. Change the database driver to "PDO (Mysql)" in global configuration
4. Upgrade akeeba backup (with upload) to version 4.5.5

UPDATE 2: Just tested and this problem also exists in 3.4.8

@andrepereiradasilva does my fix work for weblinks?

@wilsonge is there a weblinks zip to test?

@andrepereiradasilva Use http://test5.richard-fath.de/pkg_weblinks_3.4.1_patched.zip.

@wilsonge installed @richard67 zip from URL with pdo (mysql) in strict sql mode and worked fine.

The extensions update status is shown as unknown on the control panel.
When I go to "Extensions -> Manage -> Update" and click the "Find Updates" button, it ends with this sql error:
SQLSTATE[HY000]: General error: 1364 Field 'data' doesn't have a default value
Shall I open a new issue for that? Or will you handle it with this PR here, too?

I have this problem too. Of course only in strict sql_mode

@andrepereiradasilva In the case of Akeeba Backup installation the problem I tracked down the issue. In order to work around the infamous "MySQL server has gone away" errors I have my own database driver which piggybacks on Joomla!'s db driver object. Trying to make it work on older Joomla! versions I am overriding connected() with my own. I stupidly did a $this->connection->exec('SELECT 1') and only checking for exceptions. However, even though it returns an integer, PDO internally creates a cursor, like it does with all SELECT queries, but which does not make available to you. However, if you do not close the cursor that you don't have access to you get the error about having open queries. Ugh.

So, it was my fault. It only happens on the second update / reinstallation. However, it seems that I must have uncorked some kind of genie's bottle with this issue report to George because here we are with a bunch of other issues regarding PDOMySQL. Sorry.

OK I'm going to merge this as we have tests here and Nic's solved his Akeeba Backup Issue. I am going to try and fix the language issue and find updates issues before I PR turning off strict mode for PDO :)

So, it was my fault. It only happens on the second update / reinstallation. However, it seems that I must have uncorked some kind of genie's bottle with this issue report to George because here we are with a bunch of other issues regarding PDOMySQL. Sorry.

no problem. actually the first one open the PDO (Mysql) strict mode "genie's bottle" has @mbabker with is mysql 5.6.29 server :)

Just because I run the default configuration from MySQL doesn't mean nothin'

I am going to try and fix the language issue and find updates issues before I PR turning off strict mode for PDO :)

Yeah, and IMHO any other strict sql mode issues should go to 3.5.1+, since this issues are all also in 3.4.8 too.