Re: Proposition for autoname columns

On Mon, Nov  2, 2020 at 05:05:29PM +0200, Eugen Konkov wrote:
> Hello Pgsql-hackers,
> 
> When selecting data from json column it named as '?column?'
> tucha=# select info->>'suma', docn from document order by id desc limit 5;
>  ?column? | docn 
> ----------+------
>  665.97   | 695
>  513.51   | 632
>  665.97   | 4804
>  492.12   | 4315
>  332.98   | 1302
> (5 rows)
> 
> It would be useful if the name of column will be autoassigned based on
> name of json key. Like at next query:
> 
> tucha=# select info->>'suma' as suma, docn from document order by id desc limit 5;
>   suma  | docn 
> --------+------
>  665.97 | 695
>  513.51 | 632
>  665.97 | 4804
>  492.12 | 4315
>  332.98 | 1302
> (5 rows)
> 
> 
> Would it be useful this auto assigned name for column from json?

I think we could do it, but it would only work if the column was output
as a single json value, and not a multi-key/value field.  I am afraid if
we tried to do it, the result would be too inconsistent to be useful.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee