Brad Berens wrote:
First, thanks everyone for the responses. Unfortunately I'm trying to
add derby support to a previously existing open source app and I'd
like to not have to rewrite the entire deployment code to do this. As
a workaround, is it possible to force a particular return from derby
so that it won't throw an exception? Could I get the effect I'm
looking for using a CASE WHEN?
Hello Brad,
What exactly are your requirements?
Can you for instance create a stored procedure to thandle the logic for
you? This would require that you use a CallableStatement instead of a
PreparedStatement (or a Statement), and that you install the stored
procedure into the database. This is not a solution if you are looking
for a portable way of doing this... The portable way would probably be
to use the metadata calls, as already mentioned by Dyre.
I am not aware of any way to force Derby to not throw an exception.
When it comes to CASE WHEN, I don't think you can issue DDL operations
as part of it.
I personally think handling the issue in the application is the easiest
way of dealing with this, but maybe someone else has some smart ideas?
regards,
--
Kristian
On Dec 17, 2007 12:21 PM, Raymond Kroeker <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
If your ultimate goal it to start over with a new schema; an
option is to rename/delete the directory within which the db exists.
Raymond Kroeker
On Dec 17, 2007 1:42 AM, < [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
Brad Berens < [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
writes:
> I've googled for this but all I can find is create
statements so I'm hoping
> someone can just give me a quick answer. I'm trying to
write some db
> creation scripts. Normally in MSSQL I would use an if
exists from the
> system tables to check whether or not to run a drop before
creating the
> table. I found the sys.systables info about derby, but I
can't seem to get
> the if clause working for that.
>
>
> IF EXISTS (SELECT * FROM sys.systables WHERE
tablename='[tablename]') DROP
> TABLE [tablename];
IF EXISTS is a non-std extension AFAICT. You can do this
portably by
using DatabaseMetaData.getTables(...). It is a bit more work
so you might
want to wrap it in a java method.
--
dt
--
---------------------------------------------------------
Raymond Kroeker
