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From Daniel John Debrunner <...@debrunners.com>
Subject Re: CREATE FUNCTION with SQL examples ?
Date Thu, 23 Dec 2004 05:45:05 GMT
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Bernd Ruehlicke wrote:

> Hmm - this "jdbc:default:connection" is a little scary to me. Suppose my
> Der by verison runs embedded in an application server which has multiple
> connections open at any time to differnt databases - how dose the
> DriverManager.getConnection("jdbc:default:connection"); know to give me
> a connection to the Derby Database ?

It just does :-)

jdbc:default:connection is always intended to return a Connection object
that is that is a proxy for the connection and transaction that is the
SQL statement calling the function or procedure. Derby handles this by
linking the connection to the current thread for the lifetime of the
JDBC call by the application, e.g. during a
PreparedStatement.executeQuery() or ResultSet.next() call. Then the
Derby driver can find the Connection for the current thread through that
mapping, when a request for jdbc:default:connection is made.


> Or do I in such cases have to be explicit and use the explicit url to
> the given Derby instance ?

No, because any connection obtained with a jdbc:derby: url would be in a
different transaction space to the connection invoking the procedure or
function.

Dan.
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