|CREATE SCHEMA(7)||PostgreSQL 13.4 Documentation||CREATE SCHEMA(7)|
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:
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.
IF NOT EXISTS
To create a schema, the invoking user must have the CREATE privilege for the current database. (Of course, superusers bypass this check.)
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;
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.