Use case-when-then in Update ORM queries for collections

[ufoscout]

To be investigated: how to handle cases in which the condition has more than one field involved?
For example, could something similar to the following query be executed?

UPDATE tablename SET
    CASE (name, id)
        WHEN ('name1', 'id1') THEN col1=5,col2=''
        WHEN ('name2', 'id2') THEN col1=3,col2='whatever'
        ELSE ...
    END;