Re: Request to add feature to the Position function - Mailing list pgsql-general

On 03/27/2017 09:15 AM, David G. Johnston wrote:
> On Mon, Mar 27, 2017 at 9:03 AM, Brian Dunavant <brian@omniti.com
> <mailto:brian@omniti.com>>wrote:
>
>     That does not return the correct answer for the original poster's
>     request.
>
>     flpg=#
>     ​​
>     select position('om' in reverse('Tomomasaaaaaaaaaaa'));
>      position
>     ----------
>            15
>     (1 row)
>
>
> ​Easy oversight to make - if you reverse the string being searched you
> must also reverse the string that you are looking for.
>
> That said the OP hasn't actually defined what they mean by "locate" when
> considered in a backward sense - some length adjustments might be needed
> to compensate for the length of the term being searched for.

I think there is also a RTL language involved, so we may need more
information to answer the question.

>
> Patches are welcomed.  Given the lack of any links to previous requests
> of this nature I'd say its not exactly a highly in-demand capability.
>
> David J.
>


--
Adrian Klaver
adrian.klaver@aklaver.com