FreeTDS Development Group

[Henry Lafleur <HLafleur AT phoenixforge.com>]

Oops! Sorry, I read the correspondence wrong. I meant Jon. (Our Frame Relay
has been out for two days, hence the late response).

Thanks,

Henry


> -----Original Message-----
> From: Bob Kline [mailto:bkline AT rksystems.com]
> Sent: Tuesday, September 12, 2000 3:35 PM
> To: TDS Development Group
> Subject: [freetds] Re: [JDBC] setObject() - not implemented
> 
> 
> Henry:
> 
> Thanks for your reply.  However, I'm a bit confused.  First, I wasn't
> the one posting the original problem, so I assume you just 
> got me mixed
> up with Jon, who was.
> 
> Also, I may be exposing some gross misunderstanding of a basic JDBC
> concept, but I'm not sure what cursors have to do with the setObject()
> method.  I had thought that setObject() was simply a thin layer
> providing a simple convenience of mapping arbitrary objects to JDBC
> types.  Help me understand how this fits in with cursor programming.
> 
> Cheers,
> Bob
> 
> On Tue, 12 Sep 2000, Henry Lafleur wrote:
> 
> > The way that freetds_jdbc is designed, it seems that it JDBC 1.0 was
> > in mind. The process seems to be:
> > 
> > 1) Take the user's (the user being a Java program) query 
> and send it to the
> > SQL server.
> > 2) Take the response from the SQL server and read it as the 
> user goes
> > through the result set using next(), if there is a result 
> set. Let the user
> > go to other result sets, if any.
> > 
> > (My description is a little oversimplified here.)
> > 
> > Given this, how would the setObject be implemented in 
> freetds_jdbc? It seems
> > that the only way to do this would be for freetds_jdbc to 
> work differently.
> > One way would be to open a cursor and keep the connection 
> open as the user
> > moves around the result set with next(), prev(), first(), last(),
> > movetoinsertrow(), etc. (I didn't verify the method names 
> here) and to
> > compute update statements using the "where current of <cursor>" SQL
> > condition. The insert statement is straightforward: use 
> Insert <table name>
> > ... In other words, implement JDBC 2.0.
> > 
> > I know that the 1.0 implementation is the current goal, but 
> has anyone
> > discussed this?
> > 
> > For your problem Bob, I use an abstraction layer on top of 
> JDBC to handle
> > table navigation and saving data back to the database. My 
> abstraction layer
> > requires that tables have keys. Without keys how do you 
> know which record in
> > the table to change? (a semi-rhetorical question) Since you 
> can't use
> > cursors, there is no way to know that the record that you 
> are looking at is
> > the only record that will be changed in an update statement 
> unless you have
> > a table-wide unique identifier. 
> > 
> > An MS-SQL timestamp field will also work as a key. This also has the
> > advantage that if the record has changed since you read it, 
> your update will
> > not change it again since timestamps change on update. You 
> would need to
> > check to see if no records were affected by the update and 
> tell the user
> > that someone else changed the record while you were looking at it.
> > 
> > Stored procedures are another solution, which brings us to 
> server-side
> > programming. They are also much faster that other solutions.
> > 
> > Henry
> > 
> > 
> > > -----Original Message-----
> > > From: Strande, Jon [mailto:JohnS AT nwpasta.com]
> > > Sent: Tuesday, September 12, 2000 12:53 PM
> > > To: TDS Development Group
> > > Subject: [freetds] Re: [JDBC] setObject() - not implemented
> > > 
> > > 
> > > Bob,
> > > 
> > > Sorry about that, I meant to write that it 
> > > does not say that it does not work. Quite a
> > > difference... My Readme says: "The prepared
> > > statement class does not have all the data 
> > > types implemented yet". Again, my apologies.
> > > 
> > > So, I am out of luck huh? 
> > > 
> > > Thanks Bob,
> > > 
> > > Jon
> > > 
> > > -----Original Message-----
> > > From: Bob Kline [mailto:bkline AT rksystems.com]
> > > Sent: Tuesday, September 12, 2000 1:58 PM
> > > To: TDS Development Group
> > > Subject: [freetds] Re: [JDBC] setObject() - not implemented
> > > 
> > > 
> > > On Tue, 12 Sep 2000, Strande, Jon wrote:
> > > 
> > > > I have searched for answer for this, so I apologize if this 
> > > is a repeated
> > > > question. 
> > > > 
> > > > NT 4.0 Sp 5
> > > > IIS 4
> > > > Tomcat 
> > > > JDK 1.3
> > > > freetds - JDBC V 1.3 1999/03/09 17:15:49
> > > > 
> > > > In the readme file it says that setObject works
> > > > yet I am getting an error "not implemented" when
> > > > I call:
> > > > java.lang.Integer myInteger = new... etc.
> > > > myPreparedStatement.setObject(i, myInteger);
> > > > 
> > > 
> > > The README file that I have doesn't say what yours does.  The 
> > > one I have
> > > says that getObject() is implemented for all SQLServer 
> datatypes, but
> > > says nothing whatsoever about setObject() (which is indeed not
> > > implemented).  Where did you get your copy of the README file?
> > > 
> > > -- 
> > > Bob Kline
> > > mailto:bkline AT rksystems.com
> > > http://www.rksystems.com
> > > 
> > > 
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> 
> -- 
> Bob Kline
> mailto:bkline AT rksystems.com
> http://www.rksystems.com
> 
> 
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