PostgreSQL/Select Query/Query Expressions

Using expressions and constants

postgres=#
postgres=# -- Using expressions and constants
postgres=#
postgres=# SELECT 2 + 2, pi(), "PostgreSQL is more than a calculator!";
 ?column? |        pi        |               ?column?
----------+------------------+---------------------------------------
        4 | 3.14159265358979 | PostgreSQL is more than a calculator!
(1 row)
postgres=#