I think you need to take a step back and pause for a minute to clear your mind.
Now, try:
SELECT * FROM os_customer_master WHERE updated_by is null;
and then:
SELECT * FROM os_customer_master WHERE updated_by is not null;
One of these will show you the tuples you are looking for. If it's the first
then it was a simple misunderstanding. If it's the second there is something
else going on if there should be NULLs. Look for rows with nothing shown for
this column, if there are any they must have invalid data which can't be
converted to string form, or can be converted to string form but are converted
to a zero length string or one with spaces.
Well it's a starting point; if not entirely accurate it's probably accurate
enough for a now considering it's probably just a misunderstanding.
--
Nigel Andrews
On Tue, 26 Nov 2002, Savita wrote:
> Hi Tino,
>
> These query does not work.
>
>
> Tino Wildenhain wrote:
>
> > Hi Savita,
> >
> > --On Dienstag, 26. November 2002 16:02 +0530 Savita <savita@india.hp.com>
> > wrote:
> >
> > > Hi,
> > > I am able to insert the null field using \N in the text file,but while
> > > retiving the data I am not able to retrive it.
> > >
> > > After inserting data I tried this select statement
> > >
> > > select * from os_customer_master where updated_by=' ';
> > > and
> > > select * from os_customer_master where updated_by=null;
> > >
> > > but it gives 0 rows.then how will I select this values.
> >
> > Nothing to do with copy :)
> > Just try:
> >
> > select * from os_customer_master where isnull updated_by;
> >
> > Regards
> > Tino
>