mirror of
https://github.com/postgres/postgres.git
synced 2025-11-09 06:21:09 +03:00
More editing of reference pages.
This commit is contained in:
Peter Eisentraut
@@ -1,5 +1,5 @@
|
||||
<!--
|
||||
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_view.sgml,v 1.21 2002/11/21 23:34:43 petere Exp $
|
||||
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_view.sgml,v 1.22 2003/04/22 10:08:08 petere Exp $
|
||||
PostgreSQL documentation
|
||||
-->
|
||||
|
||||
@@ -8,136 +8,26 @@ PostgreSQL documentation
|
||||
<refentrytitle id="SQL-CREATEVIEW-TITLE">CREATE VIEW</refentrytitle>
|
||||
<refmiscinfo>SQL - Language Statements</refmiscinfo>
|
||||
</refmeta>
|
||||
|
||||
<refnamediv>
|
||||
<refname>
|
||||
CREATE VIEW
|
||||
</refname>
|
||||
<refpurpose>
|
||||
define a new view
|
||||
</refpurpose>
|
||||
<refname>CREATE VIEW</refname>
|
||||
<refpurpose>define a new view</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<refsynopsisdivinfo>
|
||||
<date>2000-03-25</date>
|
||||
</refsynopsisdivinfo>
|
||||
<synopsis>
|
||||
CREATE [ OR REPLACE ] VIEW <replaceable class="PARAMETER">view</replaceable> [ ( <replaceable
|
||||
class="PARAMETER">column name list</replaceable> ) ] AS SELECT <replaceable class="PARAMETER">query</replaceable>
|
||||
</synopsis>
|
||||
|
||||
<refsect2 id="R2-SQL-CREATEVIEW-1">
|
||||
<refsect2info>
|
||||
<date>2000-03-25</date>
|
||||
</refsect2info>
|
||||
<title>
|
||||
Inputs
|
||||
</title>
|
||||
<para>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">view</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The name (optionally schema-qualified) of a view to be created.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">column name list</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
An optional list of names to be used for columns of the view.
|
||||
If given, these names override the column names that would be
|
||||
deduced from the SQL query.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">query</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
An SQL query (that is, a <command>SELECT</> statement)
|
||||
which will provide the columns and rows of the view.
|
||||
</para>
|
||||
<para>
|
||||
Refer to <xref linkend="sql-select" endterm="sql-select-title"> for more information
|
||||
about valid arguments.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</refsect2>
|
||||
|
||||
<refsect2 id="R2-SQL-CREATEVIEW-2">
|
||||
<refsect2info>
|
||||
<date>2000-03-25</date>
|
||||
</refsect2info>
|
||||
<title>
|
||||
Outputs
|
||||
</title>
|
||||
<para>
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><computeroutput>
|
||||
CREATE VIEW
|
||||
</computeroutput></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The message returned if the view is successfully created.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><computeroutput>
|
||||
ERROR: Relation '<replaceable class="parameter">view</replaceable>' already exists
|
||||
</computeroutput></term>
|
||||
<listitem>
|
||||
<para>
|
||||
This error occurs if the view specified already exists in the database.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><computeroutput>
|
||||
WARNING: Attribute '<replaceable class="parameter">column</replaceable>' has an unknown type
|
||||
</computeroutput></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The view will be created having a column with an unknown type
|
||||
if you do not specify it. For example, the following command gives
|
||||
a warning:
|
||||
<programlisting>
|
||||
CREATE VIEW vista AS SELECT 'Hello World'
|
||||
</programlisting>
|
||||
|
||||
whereas this command does not:
|
||||
|
||||
<programlisting>
|
||||
CREATE VIEW vista AS SELECT text 'Hello World'
|
||||
</programlisting>
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</refsect2>
|
||||
<synopsis>
|
||||
CREATE [ OR REPLACE ] VIEW <replaceable class="PARAMETER">name</replaceable> [ ( <replaceable
|
||||
class="PARAMETER">column_name</replaceable> [, ...] ) ] AS <replaceable class="PARAMETER">query</replaceable>
|
||||
</synopsis>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1 id="R1-SQL-CREATEVIEW-1">
|
||||
<refsect1info>
|
||||
<date>2000-03-25</date>
|
||||
</refsect1info>
|
||||
<title>
|
||||
Description
|
||||
</title>
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para>
|
||||
<command>CREATE VIEW</command> defines a view of a query.
|
||||
The view is not physically materialized. Instead, a query
|
||||
rewrite rule (an <literal>ON SELECT</> rule) is automatically generated to
|
||||
support SELECT operations on views.
|
||||
<command>CREATE VIEW</command> defines a view of a query. The view
|
||||
is not physically materialized. Instead, the query is run everytime
|
||||
the view is referenced in a query.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
@@ -150,19 +40,87 @@ CREATE VIEW vista AS SELECT text 'Hello World'
|
||||
<para>
|
||||
If a schema name is given (for example, <literal>CREATE VIEW
|
||||
myschema.myview ...</>) then the view is created in the
|
||||
specified schema. Otherwise it is created in the current schema (the one
|
||||
at the front of the search path; see <literal>CURRENT_SCHEMA()</>).
|
||||
specified schema. Otherwise it is created in the current schema.
|
||||
The view name must be distinct from the name of any other view, table,
|
||||
sequence, or index in the same schema.
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect2 id="R2-SQL-CREATEVIEW-3">
|
||||
<refsect2info>
|
||||
<date>2000-03-25</date>
|
||||
</refsect2info>
|
||||
<title>
|
||||
Notes
|
||||
</title>
|
||||
<refsect1>
|
||||
<title>Parameters</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">name</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The name (optionally schema-qualified) of a view to be created.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">column_name</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
An optional list of names to be used for columns of the view.
|
||||
If not given, the column names are deduced from the query.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><replaceable class="parameter">query</replaceable></term>
|
||||
<listitem>
|
||||
<para>
|
||||
A query (that is, a <command>SELECT</> statement) which will
|
||||
provide the columns and rows of the view.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Refer to <xref linkend="sql-select" endterm="sql-select-title">
|
||||
for more information about valid queries.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Diagnostics</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><computeroutput>CREATE VIEW</computeroutput></term>
|
||||
<listitem>
|
||||
<para>
|
||||
Message returned if the view was successfully created.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><computeroutput>WARNING: Attribute '<replaceable class="parameter">column</replaceable>' has an unknown type</computeroutput></term>
|
||||
<listitem>
|
||||
<para>
|
||||
The view will be created having a column with an unknown type if
|
||||
you do not specify it. For example, the following command gives
|
||||
this warning:
|
||||
<programlisting>
|
||||
CREATE VIEW vista AS SELECT 'Hello World'
|
||||
</programlisting>
|
||||
whereas this command does not:
|
||||
<programlisting>
|
||||
CREATE VIEW vista AS SELECT text 'Hello World'
|
||||
</programlisting>
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Notes</title>
|
||||
|
||||
<para>
|
||||
Currently, views are read only: the system will not allow an insert,
|
||||
@@ -175,100 +133,79 @@ CREATE VIEW vista AS SELECT text 'Hello World'
|
||||
<para>
|
||||
Use the <command>DROP VIEW</command> statement to drop views.
|
||||
</para>
|
||||
</refsect2>
|
||||
</refsect1>
|
||||
|
||||
<refsect1 id="R1-SQL-CREATEVIEW-2">
|
||||
<title>
|
||||
Usage
|
||||
</title>
|
||||
<para>
|
||||
Create a view consisting of all Comedy films:
|
||||
<refsect1>
|
||||
<title>Examples</title>
|
||||
|
||||
<programlisting>
|
||||
CREATE VIEW kinds AS
|
||||
<para>
|
||||
Create a view consisting of all comedy films:
|
||||
|
||||
<programlisting>
|
||||
CREATE VIEW comedies AS
|
||||
SELECT *
|
||||
FROM films
|
||||
WHERE kind = 'Comedy';
|
||||
|
||||
SELECT * FROM kinds;
|
||||
|
||||
code | title | did | date_prod | kind | len
|
||||
-------+---------------------------+-----+------------+--------+-------
|
||||
UA502 | Bananas | 105 | 1971-07-13 | Comedy | 01:22
|
||||
C_701 | There's a Girl in my Soup | 107 | 1970-06-11 | Comedy | 01:36
|
||||
(2 rows)
|
||||
</programlisting>
|
||||
</programlisting>
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1 id="R1-SQL-CREATEVIEW-3">
|
||||
<title>
|
||||
Compatibility
|
||||
</title>
|
||||
|
||||
<refsect2 id="R2-SQL-CREATEVIEW-5">
|
||||
<refsect2info>
|
||||
<date>2000-03-25</date>
|
||||
</refsect2info>
|
||||
<title>
|
||||
SQL92
|
||||
</title>
|
||||
<refsect1>
|
||||
<title>Compatibility</title>
|
||||
|
||||
<para>
|
||||
SQL92 specifies some additional capabilities for the
|
||||
<command>CREATE VIEW</command> statement:
|
||||
</para>
|
||||
<synopsis>
|
||||
CREATE VIEW <replaceable class="parameter">view</replaceable> [ <replaceable class="parameter">column</replaceable> [, ...] ]
|
||||
AS SELECT <replaceable class="parameter">expression</replaceable> [ AS <replaceable class="parameter">colname</replaceable> ] [, ...]
|
||||
FROM <replaceable class="parameter">table</replaceable> [ WHERE <replaceable class="parameter">condition</replaceable> ]
|
||||
<para>
|
||||
The SQL standard specifies some additional capabilities for the
|
||||
<command>CREATE VIEW</command> statement:
|
||||
<synopsis>
|
||||
CREATE VIEW <replaceable class="parameter">name</replaceable> [ ( <replaceable class="parameter">column</replaceable> [, ...] ) ]
|
||||
AS query
|
||||
[ WITH [ CASCADE | LOCAL ] CHECK OPTION ]
|
||||
</synopsis>
|
||||
</synopsis>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
The optional clauses for the full SQL92 command are:
|
||||
<para>
|
||||
The optional clauses for the full SQL command are:
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term>CHECK OPTION</term>
|
||||
<term><literal>CHECK OPTION</literal></term>
|
||||
<listitem>
|
||||
<para>
|
||||
This option is to do with updatable views.
|
||||
All <command>INSERT</> and <command>UPDATE</> commands on the view will be
|
||||
checked to ensure data satisfy the view-defining
|
||||
condition. If they do not, the update will be rejected.
|
||||
This option is to do with updatable views. All
|
||||
<command>INSERT</> and <command>UPDATE</> commands on the view
|
||||
will be checked to ensure data satisfy the view-defining
|
||||
condition (that is, the new data would be visible through the
|
||||
view). If they do not, the update will be rejected.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term>LOCAL</term>
|
||||
<term><literal>LOCAL</literal></term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check for integrity on this view.
|
||||
Check for integrity on this view.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term>CASCADE</term>
|
||||
<term><literal>CASCADE</literal></term>
|
||||
<listitem>
|
||||
<para>
|
||||
Check for integrity on this view and on any dependent
|
||||
view. CASCADE is assumed if neither CASCADE nor LOCAL is specified.
|
||||
Check for integrity on this view and on any dependent
|
||||
view. <literal>CASCADE</> is assumed if neither
|
||||
<literal>CASCADE</> nor <literal>LOCAL</> is specified.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</para>
|
||||
</variablelist>
|
||||
</para>
|
||||
|
||||
<para>
|
||||
<command>CREATE OR REPLACE VIEW</command> is a
|
||||
<productname>PostgreSQL</productname> language extension.
|
||||
</para>
|
||||
|
||||
</refsect2>
|
||||
<para>
|
||||
<command>CREATE OR REPLACE VIEW</command> is a
|
||||
<productname>PostgreSQL</productname> language extension.
|
||||
</para>
|
||||
</refsect1>
|
||||
</refentry>
|
||||
|
||||
|
||||
Reference in New Issue
Block a user