If your site has been migrated from J!1.5 earlier on, then you might experience problems when trying to update from 2.5.x to 3.1.5.
These instructions assume you have correctely prepped your joomla 2.5.11 install and are still having issues. (ie you have upgrade your extensions and removed those which are not compatable with j3.x etc...)
Due to the different variations of installed components, you might not see the exact error below but one very similiar.
0 - An error has occurred. SQL=INSERT INTO `jos_menu` (`id`, `menutype`, `title`, `alias`, `note`, `path`, `link`, `type`, `published`, `parent_id`, `level`, `component_id`, `checked_out`, `checked_out_time`, `browserNav`, `access`, `img`, `template_style_id`, `params`, `lft`, `rgt`, `home`, `language`, `client_id`) VALUES (23, 'main', 'com_tags', 'Tags', '', 'Tags', 'index.php?option=com_tags', 'component', 0, 1, 1, 29, 0, '0000-00-00 00:00:00', 0, 1, 'class:tags', 0, '', 45, 46, 0, '', 1);
the upgrade from j2.5.11 can be a difficult one if you arrived at j.25 via a migrated j1.5.x joomla install. the reason is that for some reason the jupgrade did not correctely migrate menu (or other possibly) id's correctely.
when you do a fresh install off joomla 2.5.11 the menu items up to 200 are reserved for future joomla menu updates for the core. No user content starts until id 201. The user created menus or in this case the demo data start at 201. some versions of joomla possibly start this at id 100
now in my case there is no gap between the core and the user data menu ids (ie i have some user menus in the 0 - 200 range) and this can rear its head when you do an upgrade because the guys at joomla expect 0-100 or 0- 200 to be empty so issues like the on i have do not happen and they can put their stuff in there.
one way of detecting this error without diving into the database is the lack of the joomla update component menu in the admin panel. You can correct this missing item by following this article -insert link-- but it will delete the menu item that is already there. If you know what you are doing just look in jos_menu and see if the range 0-200 only has joomla core stuff in it.
now my issue is when the update has almost finished it says there is a duplicate entry, in my case it is a jmedia menu item
It is the menu items that causes the upgrade issue for me.
later version of j2.5 made all new 'user content' menu items install in the jos_menu id 200+ region so this will never be an issue, but for those of use who have migrated from joomla 1.5 with jupgrade to an early version of j2.5 (early versions of jupgrade had issues in migrating menu id numbers), here is the fix
The errors in the database need fixing. But you can sucessfully upgrade to joomla 3.0.3 and then make the changes. I believe that it is after j3.0.3 the 'joomla extension' and 'joomla core' quick icon items are added. However i would make the changes to the j2.5.11 first. This note is really for reference for those on j3.0.3 having similiar issues and apart from the obvious the fix is still the same.
step 1 - copy all of you menu items (only those below 200)
As mention before the joomla updater might be missing. To fix this you need to run the following sql script to add the entery back in. You by now should have an empty 0 - 200 menu id range. This is correcting one of those damaged enteries.
- additional missing menu items.
I checked the menu items on a fresh install of joomla 2.5.11 and discovered that core menu items go up to 22. (i think in later version of j3 tags is added in at id 23)
I had a missing item, Smart Search. here is the code i used to fix the missing item:
INSERT INTO `j25_menu` (`id`, `menutype`, `title`, `alias`, `note`, `path`, `link`, `type`, `published`, `parent_id`, `level`, `component_id`, `ordering`, `checked_out`, `checked_out_time`, `browserNav`, `access`, `img`, `template_style_id`, `params`, `lft`, `rgt`, `home`, `language`, `client_id`) VALUES (21, 'menu', 'com_finder', 'Smart Search', '', 'Smart Search', 'index.php?option=com_finder', 'component', 0, 1, 1, 27, 0, 0, '0000-00-00 00:00:00', 0, 0, 'class:finder', 0, '', 41, 42, 0, '*', 1);
the quickest way to get code like this is to use phpmyadmin to export them from a fresh copy of joomla j2.5.11
If the update icons are missing on the dashboard. this is because the plugins need to be enabled. on a default 3.0 install they are enabled by default.
Go to the plugin manager and enable:
You possibly need to reinstall a component over the top if you get issues. i did, in particular k2. i had updated it to the latest version before upgrade (cannot uninstall it because it wipes the database)
Also if you have tried to update, and it failed, then you have to make shure that no tables from the update are left behind in the database, because they will also conflict!