Hi Ron,

Many thanks for your quick response.

I am sorry that I didn't make myself clear.

Let me clarify that I am not referring to the derby.jar or any other jar file 
that is shipped with the Derby database installation. I am instead referring to 
a custom jar file that contains the java code for the user-defined procedures 
written by me.

I had attached the custom jar file to the database by calling the system 
procedure sqlj.install_jar(), and had added it to the database classpath using 
the system procedure  
SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY.

I hope that this more clearly explains the issue I am facing.

-Dinesh

--- On Mon, 12/7/10, Ron Rudy <[email protected]> wrote:

From: Ron Rudy <[email protected]>
Subject: Re: Attaching a jar file to the database.
To: "Derby Discussion" <[email protected]>
Date: Monday, 12 July, 2010, 6:52 PM

Dinesh,
I'm not sure I entirely understand. The jar file(s) contains the embedded 
driver, as well as the code needed to read/write to the database.  You need to 
include Derby jar(s) each time you connect to the database in any scenario 
(embedded, network, etc.) because it dictates how you communicate.  In the case 
of the embedded database it also dictates how the database itself actually 
reads/writes data to disk. 

The jar is not "attached" to the database in any sense.  It's attached to the 
JVM that reads/writes to the database.  You typically use it behind the JDBC 
API, but it is using Derby code as its underlying implementation.

I hope this answers your question...
-Ron

On Mon, Jul 12, 2010 at 8:42 AM, Dinesh Bajaj <[email protected]> wrote:

Hi,

Kindly let me know whether a jar file only needs to be attached once to the 
database, or it needs to be attached every single time a connection to the 
database is made?


I attached a jar file to the database, and added it to the database classpath. 
This was done through code, and no exception was thrown. So, I assumed that the 
file was added to the database. Now, when I connect to the database again and 
try to call a user-defined procedure that depends  on the added jar file, the 
derby throws back the java.lang.ClassNotFoundException'.


Kindly suggest what I am doing wrong.

Regards,
Dinesh Bajaj





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