mirror of https://github.com/postgres/postgres
to create a function for it. Procedural languages now have an additional entry point, namely a function to execute an inline code block. This seemed a better design than trying to hide the transient-ness of the code from the PL. As of this patch, only plpgsql has an inline handler, but probably people will soon write handlers for the other standard PLs. In passing, remove the long-dead LANCOMPILER option of CREATE LANGUAGE. Petr JelinekREL8_5_ALPHA2_BRANCH
Tom Lane
16 years ago
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$PostgreSQL: pgsql/doc/src/sgml/ref/do.sgml,v 1.1 2009/09/22 23:43:37 tgl Exp $ |
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PostgreSQL documentation |
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--> |
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|
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<refentry id="SQL-DO"> |
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<refmeta> |
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<refentrytitle id="sql-do-title">DO</refentrytitle> |
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<manvolnum>7</manvolnum> |
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<refmiscinfo>SQL - Language Statements</refmiscinfo> |
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</refmeta> |
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|
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<refnamediv> |
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<refname>DO</refname> |
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<refpurpose>execute an anonymous code block</refpurpose> |
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</refnamediv> |
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|
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<indexterm zone="sql-do"> |
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<primary>DO</primary> |
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</indexterm> |
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|
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<indexterm zone="sql-do"> |
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<primary>anonymous code blocks</primary> |
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</indexterm> |
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|
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<refsynopsisdiv> |
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<synopsis> |
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DO <replaceable class="PARAMETER">code</replaceable> [ LANGUAGE <replaceable class="PARAMETER">lang_name</replaceable> ] |
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</synopsis> |
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</refsynopsisdiv> |
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|
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<refsect1> |
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<title>Description</title> |
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|
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<para> |
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<command>DO</command> executes an anonymous code block, or in other |
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words a transient anonymous function in a procedural language. |
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</para> |
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|
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<para> |
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The code block is treated as though it were the body of a function |
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with no parameters, returning <type>void</>. It is parsed and |
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executed a single time. |
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</para> |
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</refsect1> |
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|
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<refsect1> |
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<title>Parameters</title> |
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|
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<variablelist> |
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<varlistentry> |
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<term><replaceable class="PARAMETER">code</replaceable></term> |
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<listitem> |
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<para> |
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The procedural language code to be executed. This must be specified |
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as a string literal, just as in <command>CREATE FUNCTION</>. |
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Use of a dollar-quoted literal is recommended. |
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</para> |
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</listitem> |
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</varlistentry> |
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|
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<varlistentry> |
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<term><replaceable class="PARAMETER">lang_name</replaceable></term> |
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<listitem> |
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<para> |
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The name of the procedural language the code is written in. |
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If omitted, the default is determined by the runtime parameter |
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<xref linkend="guc-default-do-language">. |
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</para> |
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</listitem> |
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</varlistentry> |
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</variablelist> |
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</refsect1> |
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|
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<refsect1> |
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<title>Notes</title> |
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|
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<para> |
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The procedural language to be used must already have been installed |
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into the current database by means of <command>CREATE LANGUAGE</>. |
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</para> |
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|
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<para> |
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The user must have <literal>USAGE</> privilege for the procedural |
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language, or must be a superuser if the language is untrusted. |
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This is the same privilege requirement as for creating a function |
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in the language. |
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</para> |
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</refsect1> |
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|
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<refsect1 id="sql-do-examples"> |
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<title id="sql-do-examples-title">Examples</title> |
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<para> |
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Execute a simple PL/pgsql loop without needing to create a function: |
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<programlisting> |
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DO $$ |
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DECLARE r record; |
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BEGIN |
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FOR r IN SELECT rtrim(roomno) AS roomno, comment FROM Room ORDER BY roomno |
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LOOP |
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RAISE NOTICE '%, %', r.roomno, r.comment; |
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END LOOP; |
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END$$; |
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</programlisting> |
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</para> |
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</refsect1> |
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<refsect1> |
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<title>Compatibility</title> |
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|
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<para> |
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There is no <command>DO</command> statement in the SQL standard. |
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</para> |
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</refsect1> |
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|
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<refsect1> |
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<title>See Also</title> |
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|
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<simplelist type="inline"> |
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<member><xref linkend="sql-createlanguage" endterm="sql-createlanguage-title"></member> |
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</simplelist> |
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</refsect1> |
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</refentry> |
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