Assuming you got Tiki via SVN, you can easily update using:
Or you can check in tiki-admin.php?page=general
Upgrade all your files to the latest version on the current branch (Ex.: from 6.x to 6.y) or latest version of trunk.
svn update -r 43705
This can be used to downgrade as well. But keep in mind that your database structure can't be automatically downgraded. Database structure typically doesn't change much between minor revisions.
This can be on a cron job.
You can upgrade from 2.x to any later version, in one step. All data migration files are included in each version. For example, from 4.x->7.x, 2.x->6.x, etc.
This is when you switch from one branch to another. When you switch (especially from an old version), you will perhaps get an error message about some directories or files that were not previously in version control (ex.: templates_c). This could be "svn: Working copy 'temp/cache' is missing or not locked". If these are directories that you didn't customize (very likely), you can simply delete them and try again. Otherwise, rename them, and you can manually merge your changes back in later. This is caused because we reorganized the code.
Here is a typical error and how to resolve
svn: Failed to add directory 'lib/jquery/jquery-ui': an unversioned directory of the same name already exists
Delete problematic directory
rm -rf lib/jquery/jquery-ui
and run svn update again
svn switch https://svn.code.sf.net/p/tikiwiki/code/branches/12.x . svn up
svn switch https://svn.code.sf.net/p/tikiwiki/code/branches/15.x . svn up
svn switch https://svn.code.sf.net/p/tikiwiki/code/branches/17.x . svn up
Note : When switching from a from 16x to 17x some error caused by changes in the way Tiki set or handle Composer may occurs.
You may have to delete caches or some files from previous install.
Fatal error: Uncaught exception 'Symfony\Component\DependencyInjection\Exception\InvalidArgumentException' with message 'You cannot set service "service_container".'
Is solved by deleting : temp/cache/container.php
svn switch https://svn.code.sf.net/p/tikiwiki/code/branches/18.x . svn up
svn switch https://svn.code.sf.net/p/tikiwiki/code/branches/21.x . svn up
svn switch https://svn.code.sf.net/p/tikiwiki/code/trunk . svn up
svn switch https://svn.code.sf.net/p/tikiwiki/code/tags/6.4/ .
This can be on a cron job, if you indicate the user & group params.
There is no database downgrade so make a backup before you proceed.
Upon install, _htaccess must be renamed .htaccess
Because of this, svn up doesn't keep it up to date.
To see if there was a change, you can do:
diff _htaccess .htaccess
If there is a difference, you can delete .htaccess and rename _htaccess to .htaccess
From web, visit tiki-admin_system.php?do=all
php console.php cache:clear