Redmine

This would help to use redmine issues referenced to a resource inventory,
or a CMDB.
Basically we'd insert cmdb data into redmine mysql tables and we'd like to define
a custom field based on query results, for example, select service_name from service_list,
and set it as a required field for defined trackers.
As it would be a very long list it would be perfect to have the query "dynamically" executed by
another value, which would be used in the where clause.
For example, we would have a Category custom field (database, system, hardware) and would use the
value to shorten the query defined.