To add to what Jeff says - just because the standard definition is X, doesn't mean that company Y will follow that. For example, I was a DBA by title, but I also created and maintained an ETL process and designed reports around the ETL (along with the rest of the team). Plus I did C# application development and VB6 development, was in charge of licensing for all the tools, and what you'd expect from a DBA (monitoring, tuning, backup/recovery, permissions, installation, upgrades, etc).
In my experience, the job description will tell you what your job duties are, the title is just how the workplace identifies your role. So you MAY be hired as a Database Developer but end up doing a lot of backup/restore operations and working with the DR plan. Are those "developer" duties, not usually. But if the workplace needs the developer to be able to handle some DBA duties as well AND that is in the job description, then the applicant should be able to handle it.
The exception to the above is in very mature and large organizations OR unionized organizations where the job title is using a fairly well defined standard. But even in those cases, the job description should define what the job is.
A good example of this - if the company is hiring a "DBA" and that was all you had to go on, would you apply? No. Of course not. Is that an Oracle DBA, SQL Server DBA, MySQL DBA, or what? As far as you know, they could be running Excel as their "database" application and expect you to administer it. And even if they had a well defined database system in place (SQL Server for example), if they don't tell you what it is, how can you apply? If it was a Sr. DBA position, I would expect that you can hit the ground running ,but if you had 10 years experience on Oracle and knew it inside out, and I am expecting you to work in SQL Server, I don't want you spending the first few months either trying to convince the company to switch to Oracle OR doing training so you can do some DBA work.
In my opinion - the job description is FAR more important than the job title.
Now, what I would do in your position - if you think you are qualified for the job, apply. If you meet 50% of the requirements, apply. If the job sounds fun and is not a Sr. level position, apply. If it is Sr. level, they likely want a lot of experience, but if you have that, apply! If you don't apply you won't get the job. If you do apply, AND get an interview, you can at least ask questions and see what they were looking for and if you still think you would be a good fit. I say the meet 50% of the requirements because sometimes the requirements are a lot higher than what you can do because they want confident people. And if you show you can learn and are a quick learner, you may get the position.
The above is all just my opinion on what you should do.
As with all advice you find on a random internet forum - you shouldn't blindly follow it. Always test on a test server to see if there is negative side effects before making changes to live!