summaryrefslogtreecommitdiffstats
path: root/doc/src/sgml/html/sql-createconversion.html
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /doc/src/sgml/html/sql-createconversion.html
parentInitial commit. (diff)
downloadpostgresql-14-upstream.tar.xz
postgresql-14-upstream.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'doc/src/sgml/html/sql-createconversion.html')
-rw-r--r--doc/src/sgml/html/sql-createconversion.html72
1 files changed, 72 insertions, 0 deletions
diff --git a/doc/src/sgml/html/sql-createconversion.html b/doc/src/sgml/html/sql-createconversion.html
new file mode 100644
index 0000000..726ccb4
--- /dev/null
+++ b/doc/src/sgml/html/sql-createconversion.html
@@ -0,0 +1,72 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>CREATE CONVERSION</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-createcollation.html" title="CREATE COLLATION" /><link rel="next" href="sql-createdatabase.html" title="CREATE DATABASE" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">CREATE CONVERSION</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-createcollation.html" title="CREATE COLLATION">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-createdatabase.html" title="CREATE DATABASE">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="SQL-CREATECONVERSION"><div class="titlepage"></div><a id="id-1.9.3.60.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">CREATE CONVERSION</span></h2><p>CREATE CONVERSION — define a new encoding conversion</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
+CREATE [ DEFAULT ] CONVERSION <em class="replaceable"><code>name</code></em>
+ FOR <em class="replaceable"><code>source_encoding</code></em> TO <em class="replaceable"><code>dest_encoding</code></em> FROM <em class="replaceable"><code>function_name</code></em>
+</pre></div><div class="refsect1" id="SQL-CREATECONVERSION-DESCRIPTION"><h2>Description</h2><p>
+ <code class="command">CREATE CONVERSION</code> defines a new conversion between
+ two character set encodings.
+ </p><p>
+ Conversions that are marked <code class="literal">DEFAULT</code> can be used for
+ automatic encoding conversion between client and server. To support that
+ usage, two conversions, from encoding A to B <span class="emphasis"><em>and</em></span>
+ from encoding B to A, must be defined.
+ </p><p>
+ To be able to create a conversion, you must have <code class="literal">EXECUTE</code> privilege
+ on the function and <code class="literal">CREATE</code> privilege on the destination schema.
+ </p></div><div class="refsect1" id="id-1.9.3.60.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">DEFAULT</code></span></dt><dd><p>
+ The <code class="literal">DEFAULT</code> clause indicates that this conversion
+ is the default for this particular source to destination
+ encoding. There should be only one default encoding in a schema
+ for the encoding pair.
+ </p></dd><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p>
+ The name of the conversion. The conversion name can be
+ schema-qualified. If it is not, the conversion is defined in the
+ current schema. The conversion name must be unique within a
+ schema.
+ </p></dd><dt><span class="term"><em class="replaceable"><code>source_encoding</code></em></span></dt><dd><p>
+ The source encoding name.
+ </p></dd><dt><span class="term"><em class="replaceable"><code>dest_encoding</code></em></span></dt><dd><p>
+ The destination encoding name.
+ </p></dd><dt><span class="term"><em class="replaceable"><code>function_name</code></em></span></dt><dd><p>
+ The function used to perform the conversion. The function name can
+ be schema-qualified. If it is not, the function will be looked
+ up in the path.
+ </p><p>
+ The function must have the following signature:
+
+</p><pre class="programlisting">
+conv_proc(
+ integer, -- source encoding ID
+ integer, -- destination encoding ID
+ cstring, -- source string (null terminated C string)
+ internal, -- destination (fill with a null terminated C string)
+ integer, -- source string length
+ boolean -- if true, don't throw an error if conversion fails
+) RETURNS integer;
+</pre><p>
+ The return value is the number of source bytes that were successfully
+ converted. If the last argument is false, the function must throw an
+ error on invalid input, and the return value is always equal to the
+ source string length.
+ </p></dd></dl></div></div><div class="refsect1" id="SQL-CREATECONVERSION-NOTES"><h2>Notes</h2><p>
+ Neither the source nor the destination encoding can
+ be <code class="literal">SQL_ASCII</code>, as the server's behavior for cases
+ involving the <code class="literal">SQL_ASCII</code> <span class="quote">“<span class="quote">encoding</span>”</span> is
+ hard-wired.
+ </p><p>
+ Use <code class="command">DROP CONVERSION</code> to remove user-defined conversions.
+ </p><p>
+ The privileges required to create a conversion might be changed in a future
+ release.
+ </p></div><div class="refsect1" id="SQL-CREATECONVERSION-EXAMPLES"><h2>Examples</h2><p>
+ To create a conversion from encoding <code class="literal">UTF8</code> to
+ <code class="literal">LATIN1</code> using <code class="function">myfunc</code>:
+</p><pre class="programlisting">
+CREATE CONVERSION myconv FOR 'UTF8' TO 'LATIN1' FROM myfunc;
+</pre></div><div class="refsect1" id="SQL-CREATECONVERSION-COMPAT"><h2>Compatibility</h2><p>
+ <code class="command">CREATE CONVERSION</code>
+ is a <span class="productname">PostgreSQL</span> extension.
+ There is no <code class="command">CREATE CONVERSION</code>
+ statement in the SQL standard, but a <code class="command">CREATE TRANSLATION</code>
+ statement that is very similar in purpose and syntax.
+ </p></div><div class="refsect1" id="SQL-CREATECONVERSION-SEEALSO"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-alterconversion.html" title="ALTER CONVERSION"><span class="refentrytitle">ALTER CONVERSION</span></a>, <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a>, <a class="xref" href="sql-dropconversion.html" title="DROP CONVERSION"><span class="refentrytitle">DROP CONVERSION</span></a></span></div></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-createcollation.html" title="CREATE COLLATION">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-createdatabase.html" title="CREATE DATABASE">Next</a></td></tr><tr><td width="40%" align="left" valign="top">CREATE COLLATION </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> CREATE DATABASE</td></tr></table></div></body></html> \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 09:57:23 +0000