Java Reference
In-Depth Information
able. The other concurrency type is
ResultSet.CONCUR_UPDATABLE
, which sig-
nifies an updatable
ResultSet
object.
In the solution to this recipe, a
PreparedStatement
object is used, and the
code to create a
PreparedStatement
object that has the ability to generate a scrol-
lable
ResultSet
looks like the following line:
pstmt = conn.prepareStatement(sql,
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
Once the
PreparedStatement
has been created as such, a scrollable
Res-
ultSet
is returned. You can traverse in several directions using a scrollable
Res-
ultSet
by calling the
ResultSet
methods indicating the direction you want to
move or the placement that you want to be. The following line of code will retrieve the
first record within the
ResultSet
:
ResultSet rs = pstmt.executeQuery();
rs.first();
The solution to this recipe demonstrates a few different scroll directions. Specific-
ally, you can see that the
ResultSet first(), next(), last()
, and
pre-
vious()
methods are called in order to move to different positions within the
Res-
ultSet
. For a complete reference to the
ResultSet
object, see the online docu-
mentation that can be found at
http://docs.oracle.com/javase/8/docs/
Scrollable
ResultSet
objects have a niche in application development. They are
one of those niceties that are there when you need them, but they are also something
that you might not need very often.
13-9. Creating an Updatable ResultSet
Problem
