Check out example codes for "how to list columns for particular tables in postgresql". It will help you in understanding the concepts better.

Code Example 1

select t.table_schema,
       t.table_name
from information_schema.tables t
inner join information_schema.columns c on c.table_name = t.table_name 
                                and c.table_schema = t.table_schema
where c.column_name = 'last_name'
      and t.table_schema not in ('information_schema', 'pg_catalog')
      and t.table_type = 'BASE TABLE'
order by t.table_schema;
Code has been copied

Code Example 2

SELECT *
  FROM information_schema.columns
 WHERE table_schema = 'your_schema'
   AND table_name   = 'your_table'
     ;

Learn ReactJs, React Native from akashmittal.com