Re: get first and last row in one sql as two columns

Thanks for suggestion. I could use two separate sqls, but I am looking to
get it in a single sql.
I just compiled and installed (under postgres id) first_last_agg C
extension.
http://pgxn.org/dist/first_last_agg/
it WORKED under postgres user with sample
select first(column1), last(column1) from (values (null),(1),(3),(null)) as
x
but somehow when I run under other users, it say

ERROR: function first(integer) does not exist

below is the control file , I can not find out why I can not run under
other user ids.
Any help would be appreciated.

# first_last_agg extension
comment = 'first() and last() aggregate functions'
default_version = '0.1.4'
module_pathname = '$libdir/first_last_agg'
relocatable = false
schema = pg_catalog
superuser = false

On Wed, Sep 2, 2015 at 7:47 PM, Melvin Davidson <melvin6925(at)gmail(dot)com>
wrote:

> Try this:
>
> SELECT
> (SELECT <your_column>
> FROM <your_table>
> ORDER BY <your_column> offset 0 LIMIT 1) ,
> (SELECT <your_column>
> FROM <your_table>
> ORDER BY <your_column> OFFSET (SELECT COUNT(*) ) LIMIT 1)
> FROM <your_table> LIMIT 1;
>
>
> On Wed, Sep 2, 2015 at 7:27 PM, Rob Sargent <robjsargent(at)gmail(dot)com> wrote:
>
>> On 09/02/2015 05:14 PM, Tom Smith wrote:
>>
>> Hi:
>>
>> I need to get the first and last tow in one sql like below
>>
>> select first(col1), last(col1) from table order by col1
>>
>> I saw some posting in wiki with a custom function (or C extention)
>> to do this. Is it widely used and reliable?
>> https://wiki.postgresql.org/wiki/First/last_(aggregate)
>>
>> I am wondering why these two functions are not part of postgresql built-in
>> functions as it has many use cases
>>
>> Thanks
>>
>> If you're ordering by col1, does
>>
>> select min(col1), max(col1) from table order by col1
>>
>> not do the trick;
>>
>
>
>
> --
> *Melvin Davidson*
> I reserve the right to fantasize. Whether or not you
> wish to share my fantasy is entirely up to you.
>