Re: [SQL] quote_nullable alternative?

[Philippe Lang]

[EMAIL PROTECTED] wrote:
> Hi,
> 
> There has been a recent discussion on the hacker mailing-list
> recently, regarding a new patch for postgresql, that returns 'NULL'
> instead of NULL when a NULL value is passed as a parameter.  
> 
> It's exactly what I need on my 8.2.5 server.
> 
> Is there an alternative to patching the server in order to get that
> kind of feature, for example with plpgsql code? 
> 
> Because of that bug:
> 
> http://www.postgresql.org/docs/faqs.FAQ.html#item4.19
> 
> ... I'm obliged to call EXECUTE at every temporary table call, and
> constructing the query string where parameters can be NULL is really
> a nightmare...  
> 
> Thanks

Hi,

It might not be the most elegant solution, but I ended up writing these
functions to solve my problem:


CREATE OR REPLACE FUNCTION nullable_param(param text)
  RETURNS text AS
$$
  BEGIN
    IF param IS NULL THEN
      RETURN 'NULL';
    ELSE
      RETURN '''' || param || '''';
    END IF;
  END
$$
  LANGUAGE 'plpgsql' VOLATILE;

  CREATE OR REPLACE FUNCTION nullable_param(param varchar)
  RETURNS varchar AS
$$
  BEGIN
    IF param IS NULL THEN
      RETURN 'NULL';
    ELSE
      RETURN '''' || param || '''';
    END IF;
  END
$$
  LANGUAGE 'plpgsql' VOLATILE;

CREATE OR REPLACE FUNCTION nullable_param(param decimal)
  RETURNS varchar AS
$$
  BEGIN
    IF param IS NULL THEN
      RETURN 'NULL';
    ELSE
      RETURN CAST(param AS varchar);
    END IF;
  END
$$
  LANGUAGE 'plpgsql' VOLATILE;

CREATE OR REPLACE FUNCTION nullable_param(param int)
  RETURNS varchar AS
$$
  BEGIN
    IF param IS NULL THEN
      RETURN 'NULL';
    ELSE
      RETURN CAST(param AS varchar);
    END IF;
  END
$$
  LANGUAGE 'plpgsql' VOLATILE;

CREATE OR REPLACE FUNCTION nullable_param(param date)
  RETURNS varchar AS
$$
  BEGIN
    IF param IS NULL THEN
      RETURN 'NULL';
    ELSE
      RETURN '''' || param || '''';
    END IF;
  END
$$
  LANGUAGE 'plpgsql' VOLATILE;



Regards,

Philippe

---------------------------(end of broadcast)---------------------------
TIP 4: Have you searched our list archives?

               http://archives.postgresql.org