DROP SCHEMA

Drop a schema from the database.

DROP SCHEMA [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]
IF EXISTS
Do not return a warning if the schema does not exist.
name
Name the schema to drop. You can drop multiple schemas with one statement.
CASCADE
If other objects depend on the schema, such as tables and views, drop them as well.
RESTRICT
If other objects depend on the schema, do not drop the schema. This is the default.
For example:
premdb=# drop schema premdb;
DROP SCHEMA
For example, attempt to drop a schema that has a dependent table:
premdb=# drop schema bobr;
ERROR:  cannot drop schema bobr because other objects depend on it
DETAIL:  table bobr.new depends on schema bobr
HINT:  Use DROP ... CASCADE to drop the dependent objects too.
premdb=# drop schema bobr cascade;
DROP SCHEMA