Dear Freind, Database Testing is not compleate different 
one, if u are doing manual tesing for a web based 
application with different logins (customer login, business 
login) and different drop downlists for these logins. then 
as a tester u need to find out the database that how the 
drop downlist is displaying the items (how it is grouping 
in backend) and from which table the data is coming. like 
that u need to test the scenario with database 
simultaniously.
its upto my knowledge. pls tell me if any

Hi, in general database testing will be also done by the
tester while doing manual or automation testing to find out
whether all the data is getting refleceted in the data base
or not. For every application thre will be a seeded data
beside that tester will cretae, update or delete the data
and more over every application has its API where in it
internally calls either a pragramm or a prosedure(API
Testing), in these type of scenarios we have to check for
whther data is reflecting in database and to check whether
all subroutines are called when application is invoking them
or not.
Its the example from my side to explain about Database tesing.