Need sql Update statement to update Purchase category values

Hi Folks,

I Need sql Update statement to update Purchase category values could someone share this as it is case sensitive please share the update statement.

I tried below one but getting error

UPDATE MTL_CATEGORIES_V

  SET SEGMENT1 = CASE SEGMENT1

        When 'BDE Building Wareh Repai' Then 'BDE Reparatur Gebäude'

        When 'BDE Buildings insurance' Then 'BDE Versicherung Gebäude'

        END

 WHERE (Select * from MTL_CATEGORIES_V where STRUCTURE_NAME ='XX1_PO_CATEGORY');