Upgrading from 3.9 to 4.1 on an Oracle database causes the loss of all social fields:

• Web URL
• ICQ
• Skype
• AIM
• Yahoo
• MSN

This issue occurs due to the query executed in user_profile_social_moveto_profilefield on the Oracle database, which fails to copy social fields into the new custom fields.

In user_profile_social_moveto_profilefield, to retrieve users that require new custom fields derived from the old social fields in the user table, the following query is executed:

$users = $DB->get_records_select('user', "$social IS NOT NULL AND $social != ''");

The condition != '' is incorrect on Oracle databases because empty fields always contain a blank character (' '), causing $users to always be empty."