Re: Selecting from joined tables (simple question)

willy gates wrote:

> Thanks for help with this one
>
> I have 2 tables
>
> DATA_STANDARD with columns ID and VALUE
>
> and
>
> DATA_EXTRA with column DS_ID and EXTRA_VALUE
>
> The idea is that extra information is stored in the DATA_EXTRA table
> when required.
>
> How do I select all values from DATA_STANDARD where there is either no
> entry in DATA_EXTRA or EXTRA_VALUE is zero.
>
> something like this?
>
> select ds.id from DATA_STANDARD ds, DATA_EXTRA de
> where
> ( ds.id not in ( select DS_ID from DATA_EXTRA ) )
> or
> (
> --Join
> ( ds.id = de.DS_ID )
> and
> ( de.extra_value is null )
> )
>
> Why is this wrong?
>
> Thanks

What is this "USe A Keyword" week?

SQL> SELECT keyword FROM v$reserved_words

   2 WHERE keyword IN ('ID', 'VALUE');

KEYWORD

SQL> Could you, perhaps, come up with worse names for your columns?

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
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