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diff --git a/doc/src/sgml/html/sql-createconversion.html b/doc/src/sgml/html/sql-createconversion.html new file mode 100644 index 0000000..77271a6 --- /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 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 15.4 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 /></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 class="navfooter"><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 15.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> CREATE DATABASE</td></tr></table></div></body></html>
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