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Re: BUG #3435: problem with substring function

From: "Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com>
To: "Carlos Quintero" <carlos(dot)quintero(dot)sspa(at)juntadeandalucia(dot)es>
Cc: pgsql-bugs(at)postgresql(dot)org
Subject: Re: BUG #3435: problem with substring function
Date: 2007-07-10 10:32:09
Message-ID: 162867790707100332l549abb1bkb18a52987586352a@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-bugs
Hello

It has little bit strange behave on 8.3. It works well, but I have to
use casting.

postgres=# select substring('1234' from to_number('3', '999999') for 3);
ERROR:  function pg_catalog.substring(unknown, numeric, integer) does not exist
LINE 1: select substring('1234' from to_number('3', '999999') for 3)...
               ^
HINT:  No function matches the given name and argument types. You
might need to add explicit type casts.

postgres=# select substring('1234' from to_number('3', '999999')::int for 3);
 substring
-----------
 34
(1 row)

Regards
Pavel Stehule



2007/7/10, Carlos Quintero <carlos(dot)quintero(dot)sspa(at)juntadeandalucia(dot)es>:
>
> The following bug has been logged online:
>
> Bug reference:      3435
> Logged by:          Carlos Quintero
> Email address:      carlos(dot)quintero(dot)sspa(at)juntadeandalucia(dot)es
> PostgreSQL version: 8.2.4
> Operating system:   Linux RedHat Enterprise 3
> Description:        problem with substring function
> Details:
>
> Hi,
>
> I like to use a numerical expression as parameter for the substring
> function, but it works always as i use regular expressions. Please, try
> this:
>
> select substring('1234' from to_number('3', '999999') for 3);
>
> What returns a empty string:
>
>  substring
> -----------
>
> (1 fila)
>
> But the right result must be this:
>
> select substring('1234' from 3 for 3);
>
>  substring
> -----------
>  34
> (1 fila)
>
> If i use other numbers, i got even some errors:
>
> select substring('1234' from to_number('33', '999999') for 3);
>
> ERROR:  la expresión regular no es válida: invalid backreference number
> CONTEXTO:  función SQL «substring» en la sentencia 1
>
> This is a sample, really i like to use an expression using date_part() as
> the first parameter for substring.
>
>
> Best Regards,
> Carlos
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>

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Next:From: FAGOT AlainDate: 2007-07-10 12:14:12
Subject: BUG #3436: inherited primary keys are not reported as primary key by the Java DatabaseMetaData
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Subject: BUG #3435: problem with substring function

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