create_schema.7

来自「PostgreSQL 8.2中增加了很多企业用户所需要的功能和性能上的提高,其开」· 7 代码 · 共 119 行

.\\" auto-generated by docbook2man-spec $Revision: 1.1.1.1 $
.TH "CREATE SCHEMA" "" "2008-01-03" "SQL - Language Statements" "SQL Commands"
.SH NAME
CREATE SCHEMA \- define a new schema

.SH SYNOPSIS
.sp
.nf
CREATE SCHEMA \fIschemaname\fR [ AUTHORIZATION \fIusername\fR ] [ \fIschema_element\fR [ ... ] ]
CREATE SCHEMA AUTHORIZATION \fIusername\fR [ \fIschema_element\fR [ ... ] ]
.sp
.fi
.SH "DESCRIPTION"
.PP
\fBCREATE SCHEMA\fR 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.
.PP
A schema is essentially a namespace:
it contains named objects (tables, data types, functions, and operators)
whose names may 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 \fBcurrent_schema\fR).
.PP
Optionally, \fBCREATE SCHEMA\fR 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.
.SH "PARAMETERS"
.TP
\fB\fIschemaname\fB\fR
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.
.TP
\fB\fIusername\fB\fR
The name of the user who will own the schema. If omitted,
defaults to the user executing the command. Only superusers
may create schemas owned by users other than themselves.
.TP
\fB\fIschema_element\fB\fR
An SQL statement defining an object to be created within the
schema. Currently, only \fBCREATE
TABLE\fR, \fBCREATE VIEW\fR, \fBCREATE
INDEX\fR, \fBCREATE SEQUENCE\fR, \fBCREATE
TRIGGER\fR and \fBGRANT\fR are accepted as clauses
within \fBCREATE SCHEMA\fR. Other kinds of objects may
be created in separate commands after the schema is created.
.SH "NOTES"
.PP
To create a schema, the invoking user must have the
CREATE privilege for the current database.
(Of course, superusers bypass this check.)
.SH "EXAMPLES"
.PP
Create a schema:
.sp
.nf
CREATE SCHEMA myschema;
.sp
.fi
.PP
Create a schema for user joe; the schema will also be
named joe:
.sp
.nf
CREATE SCHEMA AUTHORIZATION joe;
.sp
.fi
.PP
Create a schema and create a table and view within it:
.sp
.nf
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;
.sp
.fi
Notice that the individual subcommands do not end with semicolons.
.PP
The following is an equivalent way of accomplishing the same result:
.sp
.nf
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;
.sp
.fi
.SH "COMPATIBILITY"
.PP
The SQL standard allows a DEFAULT CHARACTER SET clause
in \fBCREATE SCHEMA\fR, as well as more subcommand
types than are presently accepted by
PostgreSQL.
.PP
The SQL standard specifies that the subcommands in \fBCREATE
SCHEMA\fR may appear in any order. The present
PostgreSQL implementation does not
handle all cases of forward references in subcommands; it may
sometimes be necessary to reorder the subcommands in order to avoid
forward references.
.PP
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 his schema to someone else.
.SH "SEE ALSO"
ALTER SCHEMA [\fBalter_schema\fR(7)], DROP SCHEMA [\fBdrop_schema\fR(l)]