CREATE SCHEMA
CREATE SCHEMA
7
SQL - Language Statements
CREATE SCHEMA
define a new schema
CREATE SCHEMA schema_name [ AUTHORIZATION role_specification ] [ schema_element [ ... ] ]
CREATE SCHEMA AUTHORIZATION role_specification [ schema_element [ ... ] ]
CREATE SCHEMA IF NOT EXISTS schema_name [ AUTHORIZATION role_specification ]
CREATE SCHEMA IF NOT EXISTS AUTHORIZATION role_specification
where role_specification can be:
user_name
| CURRENT_ROLE
| CURRENT_USER
| SESSION_USER
Description
CREATE SCHEMA enters a new schema
into the current database.
The schema name must be distinct from the name of any existing schema
in the current database.
A schema is essentially a namespace:
it contains named objects (tables, data types, functions, and operators)
whose names can duplicate those of other objects existing in other
schemas. Named objects are accessed either by qualifying
their names with the schema name as a prefix, or by setting a search
path that includes the desired schema(s). A CREATE command
specifying an unqualified object name creates the object
in the current schema (the one at the front of the search path,
which can be determined with the function current_schema).
Optionally, CREATE SCHEMA can include subcommands
to create objects within the new schema. The subcommands are treated
essentially the same as separate commands issued after creating the
schema, except that if the AUTHORIZATION clause is used,
all the created objects will be owned by that user.
Parameters
schema_name
The name of a schema to be created. If this is omitted, the
user_name
is used as the schema name. The name cannot
begin with pg_, as such names
are reserved for system schemas.
user_name
The role name of the user who will own the new schema. If omitted,
defaults to the user executing the command. To create a schema
owned by another role, you must be able to
SET ROLE to that role.
schema_element
An SQL statement defining an object to be created within the
schema. Currently, only CREATE
TABLE, CREATE VIEW, CREATE
INDEX, CREATE SEQUENCE, CREATE
TRIGGER and GRANT are accepted as clauses
within CREATE SCHEMA. Other kinds of objects may
be created in separate commands after the schema is created.
IF NOT EXISTS
Do nothing (except issuing a notice) if a schema with the same name
already exists. schema_element
subcommands cannot be included when this option is used.
Notes
To create a schema, the invoking user must have the
CREATE privilege for the current database.
(Of course, superusers bypass this check.)
Examples
Create a schema:
CREATE SCHEMA myschema;
Create a schema for user joe; the schema will also be
named joe:
CREATE SCHEMA AUTHORIZATION joe;
Create a schema named test that will be owned by user
joe, unless there already is a schema named test.
(It does not matter whether joe owns the pre-existing schema.)
CREATE SCHEMA IF NOT EXISTS test AUTHORIZATION joe;
Create a schema and create a table and view within it:
CREATE SCHEMA hollywood
CREATE TABLE films (title text, release date, awards text[])
CREATE VIEW winners AS
SELECT title, release FROM films WHERE awards IS NOT NULL;
Notice that the individual subcommands do not end with semicolons.
The following is an equivalent way of accomplishing the same result:
CREATE SCHEMA hollywood;
CREATE TABLE hollywood.films (title text, release date, awards text[]);
CREATE VIEW hollywood.winners AS
SELECT title, release FROM hollywood.films WHERE awards IS NOT NULL;
Compatibility
The SQL standard allows a DEFAULT CHARACTER SET clause
in CREATE SCHEMA, as well as more subcommand
types than are presently accepted by
PostgreSQL.
The SQL standard specifies that the subcommands in CREATE
SCHEMA can appear in any order. The present
PostgreSQL implementation does not
handle all cases of forward references in subcommands; it might
sometimes be necessary to reorder the subcommands in order to avoid
forward references.
According to the SQL standard, the owner of a schema always owns
all objects within it. PostgreSQL
allows schemas to contain objects owned by users other than the
schema owner. This can happen only if the schema owner grants the
CREATE privilege on their schema to someone else, or a
superuser chooses to create objects in it.
The IF NOT EXISTS option is a
PostgreSQL extension.
See Also