[horde] Upgrading Horde from 2.1 to 2.2.3: what about category_parents?

[Michael Häusler]

Hello,

I want to upgrade from Horde 2.1 to 2.2.3 and noticed that in 
scripts/db/category.sql the new column category_parents has been added 
to the table horde_categories:
   category_parents VARCHAR(255) NOT NULL

Since category_parents is defined NOT NULL without a DEFAULT value, I do 
not know how to update my existing table.

I could not find any hints in the FAQs and in the mailing lists, so I 
would be very glad, if somebody could help me out.

Regards,
Michael