How to mark selected columns of a table for display - database

Question

I use PostgreSQL 10.1 and:
CREATE TABLE human
(
id ... NOT NULL,
gender ...,
height ...,
weight ...,
eye ...,
hair ...,
...
);
I have an input form through which I insert the data. I wish an elegant and proper way by which I can SELECT which columns required to be DISPLAYED in that form, something like weight ... DISPLAYED, or eye ... NOT DISPLAYED, .
One way is to correspond NULL with DISPLAYED (when NOT NULL then display it, or when NULL then do not display it) and use information_schema which (corresponding) makes me no so happy:
Another way is to:
CREATE TABLE human_column
(
id ... NOT NULL,
characteristic character varying(...),
is_displayed boolean
);
where characteristic data are the names of the columns of human table.
Is there a better way to add a direct foreign attribute to the columns of a table? (In 51.7. pg_attribute there is a column named attoptions. Would it be used?)

Answer 1

specifying "options" for columns to define if they will be "displayed" or not seems a little overhead. Imagine you keep such list in human_column. To modify it you would need to update it with new is_displayed values. Then you would need to build column list to be selected in query.
When you create a view, you do the same (specify a list of columns to be displayed) and then you can just query the view, without need to dynamically build the query. Also you can always check the current list of included columns from catalog or information_schema.
The only "not cosy" feature of a view - you can't change columns in it, thus you have to drop and create it again.
drop/create view on demand looks cheaper to me then dynamically building query with list of columns on each select still.
demo:
db=# create view v as select oid,datname from pg_database;
CREATE VIEW
db=# select * from v;
oid | datname
-------+-----------
13505 | postgres
16384 | t
1 | template1
13504 | template0
16419 | o
(5 rows)
checking list of columns:
db=# select column_name,ordinal_position,column_default,is_nullable,data_type,character_maximum_length from information_schema.columns where table_name = 'v';
column_name | ordinal_position | column_default | is_nullable | data_type | character_maximum_length
-------------+------------------+----------------+-------------+-----------+--------------------------
oid | 1 | | YES | oid |
datname | 2 | | YES | name |
(2 rows)
same for original table:
db=# select column_name,ordinal_position,column_default,is_nullable,data_type,character_maximum_length from information_schema.columns where table_name = 'pg_database';
column_name | ordinal_position | column_default | is_nullable | data_type | character_maximum_length
---------------+------------------+----------------+-------------+-----------+--------------------------
datname | 1 | | NO | name |
datdba | 2 | | NO | oid |
encoding | 3 | | NO | integer |
datcollate | 4 | | NO | name |
datctype | 5 | | NO | name |
datistemplate | 6 | | NO | boolean |
datallowconn | 7 | | NO | boolean |
datconnlimit | 8 | | NO | integer |
datlastsysoid | 9 | | NO | oid |
datfrozenxid | 10 | | NO | xid |
datminmxid | 11 | | NO | xid |
dattablespace | 12 | | NO | oid |
datacl | 13 | | YES | ARRAY |
(13 rows)