Re: BUG #4436: (E'\\' LIKE E'\\') => f

Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > Mathieu Fenniak wrote:
> >> I noticed that (SELECT E'\\' LIKE E'\\') returns false,
>
> > I believe this is caused because backslash is the default escape
> > character for LIKE, so you need:
> > test=> SELECT E'\\' LIKE E'\\\\';
>
> Yeah. The given case is actually an invalid LIKE pattern. I wonder
> whether we should make LIKE throw error for an invalid pattern.
> You get an error for the corresponding case in regex:
>
> regression=# select E'\\' ~ E'\\';
> ERROR: invalid regular expression: invalid escape \ sequence
>
> but IIRC the LIKE code just silently ignores a trailing escape
> character.

Yes, I think we should throw an error; the original query looked odd to
me too.

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Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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