Junit test cases for Rest APIs connecting to DB

I have a JAVA rest service that interacts with the database , does some manipulation and returns the data.

I am trying to write test cases for these APIs.

I am trying to use the below link for reference to implement this.

http://ift.tt/1LvZz7y

Here, calls made to the database are suppressed and the dto is mocked with made up values.

Is there an alternate method where we actually get to run the queries w/o talking to the db , (an in-memory db may be? )

Any code sample or reference would be of great help.