There are two ways to know which version of Piwik you are using:
Updating Piwik is easy and we hope you will always use the latest version of Piwik! It is possible to update from any old version to the latest one. Please see the Update guide for further instructions.
Please see the WordPress guide on how to backup your database.
Please see the WordPress guide on how to restore your database from backup.
You can set a setting in your config/config.ini.php file as explained in this FAQ.
Ask your sysadmin to GRANT your database user INDEX privilege. This is required to CREATE, DROP, and ALTER indexes, and allow Piwik to update successfully.
It happens in rare cases that Piwik believes it has upgraded to a new version (when using the latest PHP/JS files), but that the database itself was not upgraded. This FAQ explains how to re-run the database upgrade from a particular version.
For example, this could happen if the database crashed or overloaded during the DB upgrade (we recommend to enable maintenance and run the ugprade in the command line). It could also happen if the new Piwik files in core/Updates/ haven't yet been uploaded to the latest files, but a Piwik user visits the Piwik UI and issues the partial upgrade leading to the errors.
As a result SQL error messages are often printed in some - or all - the reports. Errors messages such as
Error trying to execute the query 'CREATE TABLE [...] Base table or view already exists: 1050 Table exists or
SQLSTATE[42S22]: Column not found: 1054 Unknown column on clause or
SQLSTATE: Syntax error or access violation: 1091 Can't DROP X check that column/key exist or
Error trying to execute the query 'ALTER TABLE' SQLSTATE[42S22]: Column not found: 1054 Unknown column
The good news is that it possible in all cases to resolve the issue and not experience any data loss or other problem!
You can manually tell Piwik to run the upgrade again from the version you last good version, by running the following SQL query (eg. using a tool such as phpMyAdmin):
UPDATE `piwik_option` SET option_value = "1.X" WHERE option_name = "version_core";
Replace 1.X with the version you were using prior to upgrading, for example "1.10". After running this query, visit Piwik: you should see the upgrade screen again. You can run the upgrade in the command line if your Piwik is large, or simply click the button and wait until completion.
If you still have problems, you can get help in the forums or contact Professional Services for paid support by us.
In your config/config.ini.php add the following code: