Bugzilla: How to change flags in several bugs at once?

Question

Or is there a work-around ? If a run a query to do this directly in the back-end DB, do I risk any sort of schema corruption?

Answer 1

Most likely you only need to care about data consistency, not the schema itself, unless you interchange UPDATE with ALTER TABLE or such, and data consistency can be check by issuing a sanity check after
your change and even in case your are making something wrong which is valid for the currently used schema, but invalid in future versions, those things should be more easily fixable than schema changes.

Simply use a transaction and if everything passes and a sanity check succeeds I wouldn't have to much concerns anymore.