Thread: Possible bug with row_to_json

When using a subquery as a source for row_to_json, depending on the order of arguments it may ignore renaming a column.

jack=# create table player(
jack(#   player_id serial primary key,
jack(#   name varchar not null unique
jack(# );
NOTICE:  CREATE TABLE will create implicit sequence "player_player_id_seq" for serial column "player.player_id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "player_pkey" for table "player"
NOTICE:  CREATE TABLE / UNIQUE will create implicit index "player_name_key" for table "player"
CREATE TABLE
jack=# insert into player(name) values('Jack');
INSERT 0 1
jack=# select row_to_json(t)
jack-# from (
jack(#   select player_id as renamed, name
jack(#   from player
jack(#   order by name
jack(# ) t;
          row_to_json         
-------------------------------
 {"player_id":1,"name":"Jack"}
(1 row)


It ignored the rename.


jack=# select row_to_json(t)
from (
  select name, player_id as renamed     
  from player
  order by name
) t;
         row_to_json        
-----------------------------
 {"name":"Jack","renamed":1}
(1 row)

But here it didn't.

Is this a bug?

Jack Christensen

On Mon, Aug 5, 2013 at 5:15 PM, Jack Christensen
<jack@jackchristensen.com> wrote:
> When using a subquery as a source for row_to_json, depending on the order of
> arguments it may ignore renaming a column.
>
> jack=# create table player(
> jack(#   player_id serial primary key,
> jack(#   name varchar not null unique
> jack(# );
> NOTICE:  CREATE TABLE will create implicit sequence "player_player_id_seq"
> for serial column "player.player_id"
> NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "player_pkey"
> for table "player"
> NOTICE:  CREATE TABLE / UNIQUE will create implicit index "player_name_key"
> for table "player"
> CREATE TABLE
> jack=# insert into player(name) values('Jack');
> INSERT 0 1
> jack=# select row_to_json(t)
> jack-# from (
> jack(#   select player_id as renamed, name
> jack(#   from player
> jack(#   order by name
> jack(# ) t;
>           row_to_json
> -------------------------------
>  {"player_id":1,"name":"Jack"}
> (1 row)
>
>
> It ignored the rename.
>
>
> jack=# select row_to_json(t)
> from (
>   select name, player_id as renamed
>   from player
>   order by name
> ) t;
>          row_to_json
> -----------------------------
>  {"name":"Jack","renamed":1}
> (1 row)
>
> But here it didn't.
>
> Is this a bug?

yup.

merlin