Rick Hillegas wrote:
I would like to hook the XML type up to the network layer and the JDBC
4.0 machinery.Currently, you cannot select an XML column and return it
to the client. Nor can you insert directly into an XML column. I would
like to make the compiler accept the following statements:
select xmlColumn from fooTable;
insert into fooTable ( xmlColumn ) values ( ? );
and I would like to implement the following jdbc methods:
PreparedStatement.setSQLXML()
ResultSet.getSQLXML()
Ah, okay, I had a feeling that JDBC 4.0 was where you were headed :) I agree
there is a need for this, and I'm glad you're looking at getting the 4.0
machinery in place. Note that, in the meantime, I am working on a pre-JDBC 4.0
solution to this issue: in the document I posted to DERBY-688 yesterday, one of
the things I mention, under the "usability" section, is implicit
serialization/parsing at the JDBC level, which will allow both of the above
statements to compile. Then, the user can use 'getString' in the first case to
get the result, and 'setString' in the second to bind to an XML value. But as I
said, that's more of a solution for pre-JDBC 4.0 JVMs. To have the "setSQLXML"
and "getSQLXML" functionality that you mention is certainly a great longer term
goal for JDBC 4.0 support, as that gives the user more control over an XML value.
There will continue to be only one XML datatype--the one you have
already built a foundation for. It is just going to be more capable.
Great, this is what I was hoping. So in your original email, when you list
"SQLXML" as a new type, that's the JDBC name of the type, not the SQL name,
correct? I.e. there will _not_ be support for things like:
ij> create table xt (x sqlxml);
only
ij> create table xt (x xml);
If this is correct, then I _think_ this will be the first type in Derby where
the JDBC type name and the SQL type name differ (don't hold me to that--I only
looked briefly). That doesn't necessarily mean anything, it's just something I
find interesting.
If you want to help out with any of these tasks, I will be delighted!
I will be happy to help where I can. Right now, my "itch" is the work I'm doing
for DERBY-688, but ultimately I think we're both heading toward the same goal,
so I trust there will be opportunities for us (and anyone else interested, for
that matter) to help each other out along the way.
Thanks for the info,
Army
