postgresql/doc/src/sgml/ref/do.sgml
Peter Eisentraut 6ef2448796 Fix a whitespace issue with the man pages
There is what may actually be a mistake in our markup.  The problem is
in a situation like

<para>
 <command>FOO</command> is ...

there is strictly speaking a line break before "FOO".  In the HTML
output, this does not appear to be a problem, but in the man page
output, this shows up, so you get double blank lines at odd places.

So far, we have attempted to work around this with an XSL hack, but
that causes other problems, such as creating run-ins in places like

<acronym>SQL</acronym> <command>COPY</command>

So fix the problem properly by removing the extra whitespace.  I only
fixed the problems that affect the man page output, not all the
places.
2011-08-07 10:55:32 +03:00

129 lines
3.2 KiB
Plaintext

<!--
doc/src/sgml/ref/do.sgml
PostgreSQL documentation
-->
<refentry id="SQL-DO">
<refmeta>
<refentrytitle>DO</refentrytitle>
<manvolnum>7</manvolnum>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>DO</refname>
<refpurpose>execute an anonymous code block</refpurpose>
</refnamediv>
<indexterm zone="sql-do">
<primary>DO</primary>
</indexterm>
<indexterm zone="sql-do">
<primary>anonymous code blocks</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
DO [ LANGUAGE <replaceable class="PARAMETER">lang_name</replaceable> ] <replaceable class="PARAMETER">code</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>DO</command> executes an anonymous code block, or in other
words a transient anonymous function in a procedural language.
</para>
<para>
The code block is treated as though it were the body of a function
with no parameters, returning <type>void</>. It is parsed and
executed a single time.
</para>
<para>
The optional <literal>LANGUAGE</> clause can be written either
before or after the code block.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="PARAMETER">code</replaceable></term>
<listitem>
<para>
The procedural language code to be executed. This must be specified
as a string literal, just as in <command>CREATE FUNCTION</>.
Use of a dollar-quoted literal is recommended.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="PARAMETER">lang_name</replaceable></term>
<listitem>
<para>
The name of the procedural language the code is written in.
If omitted, the default is <literal>plpgsql</>.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
The procedural language to be used must already have been installed
into the current database by means of <command>CREATE LANGUAGE</>.
<literal>plpgsql</> is installed by default, but other languages are not.
</para>
<para>
The user must have <literal>USAGE</> privilege for the procedural
language, or must be a superuser if the language is untrusted.
This is the same privilege requirement as for creating a function
in the language.
</para>
</refsect1>
<refsect1 id="sql-do-examples">
<title id="sql-do-examples-title">Examples</title>
<para>
Grant all privileges on all views in schema <literal>public</> to
role <literal>webuser</>:
<programlisting>
DO $$DECLARE r record;
BEGIN
FOR r IN SELECT table_schema, table_name FROM information_schema.tables
WHERE table_type = 'VIEW' AND table_schema = 'public'
LOOP
EXECUTE 'GRANT ALL ON ' || quote_ident(r.table_schema) || '.' || quote_ident(r.table_name) || ' TO webuser';
END LOOP;
END$$;
</programlisting></para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
There is no <command>DO</command> statement in the SQL standard.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="sql-createlanguage"></member>
</simplelist>
</refsect1>
</refentry>