Checking The Type Of A Value

The pg_typeof() function allows you to determine the data type of anything in Postgres.

> select pg_typeof(1);
 pg_typeof
-----------
 integer
(1 row)

> select pg_typeof(true);
 pg_typeof
-----------
 boolean
(1 row)

If you try it on an arbitrary string, it is unable to disambiguate which string type (e.g. text vs varchar).

> select pg_typeof('hello');
 pg_typeof
-----------
 unknown
(1 row)

You just have to be a bit more specific.

> select pg_typeof('hello'::varchar);
     pg_typeof
-------------------
 character varying
(1 row)