It's useful to have an idea of what SQL statements need to be applied to a database to bring it compatible with the current release of EQEmu at any given time, surely.
The changelog is well-utilized for getting those needed changes out to users. The issue that comes up is that one database may require a different set of changes than another.
The solution, however, falls on the releasers of the database, not eqemu. Check with the database maintainer for information on getting it up to date, such as this thread for ProjectEQ:
http://www.projecteq.net/phpBB2/viewtopic.php?t=1679
Alternatively, what I tend to do, is look at the date of the database release, and apply all the SQL changes in the changelog after that date (unless your db maintainer is Miss Cleo, then you shouldn't be having problems with it at all, baby!)