SEO

#1 (**permalink**) 04-20-2008, 03:21 PM

A naive question: why does:

"x" LIKE "% %"

...evaluate to false but:

"x" LIKE "x %"

...evaluate to true? (The same is true of MATCHES with *s instead of
%s.)

I realise it has something to do with the trimming of trailing
whitespace before comparison (eg, "x" = "x ") - but I can't see why
the first example doesn't attempt to evaluate the same thing as the
second example as it attempts to match the wildcards.

[I've tried this on IDS 7.31.UD9, 9.40.UC7 and 10.00.FC4]

#2 (**permalink**) 04-20-2008, 03:21 PM

Bruce Preston wrote:
> A naive question: why does:
>
> "x" LIKE "% %"
>
> ..evaluate to false but:
>
> "x" LIKE "x %"
>
> ..evaluate to true? (The same is true of MATCHES with *s instead of
> %s.)
>
> I realise it has something to do with the trimming of trailing
> whitespace before comparison (eg, "x" = "x ") - but I can't see why
> the first example doesn't attempt to evaluate the same thing as the
> second example as it attempts to match the wildcards.
>
> [I've tried this on IDS 7.31.UD9, 9.40.UC7 and 10.00.FC4]

Report it to Tech Support - I think it is most likely a bug.

--
Jonathan Leffler #include <disclaimer.h>
Email: jleffler@earthlink.net, jleffler@us.ibm.com
Guardian of DBD::Informix v2005.02 -- http://dbi.perl.org/

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SEO

Unusual behaviour of LIKE and MATCHES?