Re: BLOB

From: Dirk Tschentscher <dirk.tschentscher_at_volkswagen.de>
Date: Thu, 31 Oct 2002 14:40:20 +0100
Message-ID: <aprbrv$ol54@doiweb4.volkswagen.de>

Hi Peter,
I tested it before I wrote...

The table is

CREATE TABLE td_werte_anlagen
 (

  wert_id                 NUMBER(*,0) NOT NULL,
  inhalt                     BLOB

 )

the following select stmt :

 SELECT
    WERT_ID,

    dbms_lob.getlength  (INHALT)                         col_a,
    nvl  (dbms_lob.getlength  (INHALT),0.5)            col_b,

    nvl (to_char(dbms_lob.getlength (INHALT)),'A') col_c  FROM TYKON.TD_WERTE_ANLAGEN causes this result :

WERT_ID COL_A COL_B COL_C
---------- ---------- ---------- ----------

1                                     .5                   A
226        1067444    1067444    1067444
362        147456     147456     147456
452        276080     276080     276080
600        16903330   16903330   16903330

I was surprised about the result, but from my point of view my posting is correct, or is it not ???
Where's my mistake ?

By the way, I sent my posting a little time before I saw yours, but someone stood on the line..
I don't wanted to blame you for your mail !

Regards
 Dirk

"Peter van Rijn" <p.vanrijnREMOVE_at_THISzhew.nl> schrieb im Newsbeitrag news:us2bo04c8l7gb4_at_corp.supernews.com...
> It returns 0 (zero) if the BLOB is empty (=null).
>
> Peter
>
>
> "Dirk Tschentscher" <dirk.tschentscher_at_volkswagen.de> schreef in bericht
> news:apr8ql$ol53_at_doiweb4.volkswagen.de...
> > Hi
> > what about dbms_lob.getlength(blobfield).
> > this function returns null when the field is null
> >
> > rgds
> > Dirk
> >
> > "acelestial" <acelestial_at_twp.cwellington.on.ca> schrieb im Newsbeitrag
> > news:MvYv9.124$896.10833975_at_radon.golden.net...
> > > Hi,
> > >
> > > How do I check if a blob field is empty or null?
> > > I want to update a column where the blob field is not null.
> > > I tried IS NOT NULL but it keeps on updating all the records.
> > > My syntax is:
> > > UPDATE table
> > > SET column1 = 'something'
> > > WHERE blobfield IS NOT NULL;
> > >
> > > Any help is much appreciated.
> > >
> > > Thanks,
> > > Arman
> > >
> > >
> >
> >
>
>
Received on Thu Oct 31 2002 - 07:40:20 CST