PostgreSQL - Array Function

PostgreSQL ARRAY_AGG function is used to concatenate the input values including null into an array.

To understand ARRAY_AGG function, consider the table COMPANY having records as follows:

testdb# select * from COMPANY;
 id | name  | age | address   | salary
----+-------+-----+-----------+--------
  1 | Paul  |  32 | California|  20000
  2 | Allen |  25 | Texas     |  15000
  3 | Teddy |  23 | Norway    |  20000
  4 | Mark  |  25 | Rich-Mond |  65000
  5 | David |  27 | Texas     |  85000
  6 | Kim   |  22 | South-Hall|  45000
  7 | James |  24 | Houston   |  10000
(7 rows)

Now suppose based on the above table you want to use the ARRAY_AGG, you can do so by using the following command:

testdb=# SELECT ARRAY_AGG(SALARY) FROM COMPANY;

Above PostgreSQL statement will produce the following result:

                  array_agg
---------------------------------------------
 {20000,15000,20000,65000,85000,45000,10000}