Well according to Wikipedia:
The role may include capacity planning, installation, configuration, database design, migration, performance monitoring, security, troubleshooting, as well as backup and data recovery.
I think there's a little more to it than being able to write queries, which'd make you a DBU (user) more than a DBA, I'd say. (No DBU is not a real word)
I know SQL, but I try to avoid doing most of the above stuff (not always successfully).