Re: Bug #604: string join problem

Tom Lane wrote:

> pgsql-bugs(at)postgresql(dot)org writes:
> > I have a major problem with string joining in sql query in Postgresql 7.1.3. It is always return null string if any of column has null value.
>
> This is not a bug. SQL92 6.13 general rule 2a saith:
>
> a) If either S1 or S2 is the null value, then the result of the
> <concatenation> is the null value.
>
> Consider using something like
>
> COALESCE(col1,'') || COALESCE(col2,'') || ...
>
> if you want to treat NULLs as empty strings. Also consider whether you
> shouldn't have stored the fields as empty strings in the first place.
> NULL and empty string are not at all the same thing; if your data design
> treats them as interchangeable then your design is broken, IMHO.
>
> regards, tom lane

Thanks for the reply. COALESCE is working good, however, I wrote a PL/pgSQL procedure to get more proper results.

Best Regards,
--
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Erol Ozcan mailto:erol(at)infotron(dot)com(dot)tr
Software Engineer http://www.infotron.com.tr
Tel: +90-216-4921002
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