Re: Working with CLOB's

["Joe Sam Shirah" <jshirah@xxxxxxxxxxxxx>]

    Hi Chad,

    LOBs use Locators, which are similar to a pointer or path to the actual
data.  The data itself isn't brought down on the initial select.  The reason
is that if you had images or documents of several megs ( or ) larger,
browsing or other access could be fairly slow ( understatement ).  Instead
the LOB data is materialized by additional calls.

    The reason Kristen used the getSubString() call is that is a sometimes
easier way to materialize all or portions of a CLOB than  getAsciiStream()
or getCharacterStream(), which is normal usage.

    You may want to look over my JDBC 2.0 Fundamentals tutorial, especially
the section on LOBs, at the JDC ( which this week they call the Sun
Developer Network ).  It's at:
<
http://java.sun.com/developer/onlineTraining/Database/JDBC20Intro/
>

    There's a working example for BLOBs, but I didn't do one for CLOBs,
mostly because I'm sort of philosophically against them.  All examples were
tested against  DB2/400,  DB2 Universal, and Cloudscape ( where
applicable ),  HTH,


                                                         Joe Sam

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----- Original Message ----- 
From: "cornelius, chad" <chad.cornelius@xxxxxxxxxxxxxxxxxxxx>
To: "'Java Programming on and around the iSeries / AS400'"
<java400-l@xxxxxxxxxxxx>
Sent: Wednesday, August 31, 2005 4:36 PM
Subject: RE: Working with CLOB's


> Thanks Kristen...  Is there a way to view the data using a database tool
> such as DBVisualizer or MyEclipse database perspective?
>
> Chad Cornelius, IIS
> (720) 921-7835
>
> -----Original Message-----
> From: Kristen Henry [mailto:klhnry@xxxxxxxxxxxx]
> Sent: Wednesday, August 31, 2005 2:29 PM
> To: 'Java Programming on and around the iSeries / AS400'
> Subject: RE: Working with CLOB's
>
> Using SQL do a regular select.  Then I do something like this:
>
>     if (rs.getClob("additionalcomments") !=
> null) {
>
>     Clob c =
> rs.getClob("additionalcomments");
>
> setAdditionalcomments(c.getSubString(1, (int) c.length()));
> } else {
>
> setAdditionalcomments("");
>     }
>
> I don't remember why I had to do the substring thing...
>
> Kristen
>
>
>
> > -----Original Message-----
> > From: java400-l-bounces@xxxxxxxxxxxx
> > [mailto:java400-l-bounces@xxxxxxxxxxxx] On Behalf Of cornelius, chad
> > Sent: Wednesday, August 31, 2005 2:12 PM
> > To: 'java400-l@xxxxxxxxxxxx'
> > Subject: Working with CLOB's
> >
> >
> > This is the first time I have attempted or needed to work
> > with Clob's, and am wondering how you retrieve the data
> > defined as a CLOB using SQL.  Is this even possible?  Any
> > suggestions would be greatly appreciated.
> >
> >
> >
> > Thanks,
> >
> > Chad Cornelius, IIS
> >
> > (720) 921-7835
> >
> >
> >
> > -- 
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> >
> >
>
>
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