Re: get column name passed to a function

On 11/20/2012 12:51 PM, Rob Sargent wrote:
> On 11/20/2012 01:35 PM, Adrian Klaver wrote:
>> On 11/20/2012 11:36 AM, Rhys A.D. Stewart wrote:
>>> Greetings,
>>>
>>> I'm looking to obtain the name of a column that is passed to a function,
>>> similar to xmlforest. Suggestions?
>>
>> This is going to require some more information.
>>
>> 1) What language is the function written in?
>>
>> 2) Trigger function or not?
>>
>> 3) A sample of the code?
>>
>>>
>>> Regards,
>>>
>>>
>>> Rhys
>>
>>
>
> Is this along the right line(s)?
>
>
> create or replace function f(cname text) returns table(c text)
> as
> $$
> declare
> v text;
> begin
> select 'hello' into v;
> raise notice 'Column name is %', v;
> execute 'select ' || v || ' as ' || cname;
> end;
> $$ language plpgsql;

So what you are looking to do is build dynamic queries?

If so take a look at:

http://www.postgresql.org/docs/9.2/interactive/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN

In particular:

Example 39-1. Quoting Values In Dynamic Queries

>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com