Oracle released Application Express 3.0.1 recently. With this release you can upgrade APEX within Oracle XE from 2.1 to 3.0.1 (see Oracle Database XE and Application Express 3.0.1). But how to upgrade when you already installed APEX 3.0 on XE?
There is a patch available on Metalink to upgrade from APEX 3.0 to 3.0.1. According to the Patch Set Notes Oracle9i release 2 and higher support this patch if you have APEX 3.0.0.00.20 already installed (the Patch Set Notes also includes a list of fixed bugs). In order to download the patch from Metalink, you will need a support contract (which is not included with XE).
Another option is to remove APEX 3.0 completely. After the removal, XE has APEX 2.1. (still) installed and the next step is of course to install APEX 3.0.1. The big advantage of this option is you following the main route of upgrading XE/APEX as proposed by Oracle. However there are some things to keep in mind.
As always start with making a backup of your database.
Export all applications you would like to see again in APEX 3.0.1. If you remove APEX 3.0 completely, you also remove all applications stored in the
FLOWS_030000(APEX 3.0) schema! Note that applications stored in the
FLOWS_020100schema will be migrated to
Make a backup of changed or added cascading style sheets (CSS), images and java scripts separately.
apex_3.0.1\apxremov.sqlscript (the script is the same for both versions).
apex_3.0.1\apxins.sqlscript. Check the installation log for errors.
apex_3.0.1\imagesdirectory to the
/i/directory. Also copy the previous backed up CSS, images and java scripts to the
Import all applications exported in the first step. Note that existing applications in APEX 2.1 are migrated to APEX 3.0.1 as part of the upgrade process.
Time to make a backup again.
Have a look at the APEX reports in SQL Developer, no errors any more.