<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Store 'mysql'</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2">
<link rel="start" href="index.html" title="Redland RDF Library Manual">
<link rel="up" href="redland-storage-modules.html" title="Storage Modules">
<link rel="prev" href="redland-storage-module-file.html" title="Store 'file'">
<link rel="next" href="redland-storage-module-postgresql.html" title="Store 'postgresql'">
<meta name="generator" content="GTK-Doc V1.10 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
<link rel="chapter" href="redland.html" title="Redland Overview">
<link rel="chapter" href="introduction.html" title="Introduction">
<link rel="part" href="tutorial.html" title="Part I. Tutorial">
<link rel="part" href="reference-manual.html" title="Part II. Reference Manual">
<link rel="chapter" href="objects.html" title="Objects in C">
<link rel="chapter" href="redland-storage-modules.html" title="Storage Modules">
<link rel="index" href="indexes.html" title="Index">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle">
<td><a accesskey="p" href="redland-storage-module-file.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="redland-storage-modules.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">Redland RDF Library Manual</th>
<td><a accesskey="n" href="redland-storage-module-postgresql.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr></table>
<div class="section" lang="en">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="redland-storage-module-mysql"></a>Store 'mysql'</h2></div></div></div>
<p>This module is compiled in when MySQL 3 or 4 is available. This
store provides storage using the
<a class="ulink" href="http://www.mysql.com/" target="_top">MySQL</a>
open source database including contexts. It was added in Redland
0.9.15. It has however been tested with several million triples and
deployed.</p>
<p>There are several options required with the mysql storage
in order to connect to the database. These are:</p>
<div class="itemizedlist"><ul type="disc">
<li><p><code class="literal">host</code> for the database server hostname</p></li>
<li><p><code class="literal">port</code> for the database server port (defaults to the MySQL port 3306 if not given)</p></li>
<li><p><code class="literal">database</code> for the MySQL database name (not the storage name)</p></li>
<li><p><code class="literal">user</code> for the database server user name</p></li>
<li><p><code class="literal">password</code> for the database server password</p></li>
</ul></div>
<p>NOTE: Take care exposing the password as for example, program
arguments or environment variables. The rdfproc
utility can with help this by reading the password from standard
input. Inside programs, one way to prevent storing the password in a
string is to construct a Redland hash of the storage options such as
via <code class="literal">librdf_hash_from_string</code> and use
<code class="literal">librdf_new_storage_with_options</code> to create a storage.
The rdfproc utility source code demonstrates this.
</p>
<p>The storage name parameter given to the storage constructor
<code class="literal">librdf_new_storage</code> is used inside the mysql store to
allow multiple stores inside one MySQL database instance as
parameterised with the above optiosn.</p>
<p>If boolean option <code class="literal">new</code> is given, any existing MySQL
database named by the storage option <code class="literal">database</code>, say
<span class="emphasis"><em>db</em></span> will be dropped and the appropriate new tables created.
The MySQL database <span class="emphasis"><em>db</em></span> must already exist, such as made with
the MySQL <code class="literal">create database </code><span class="emphasis"><em>db</em></span> command and the
appropriate priviledges set so that the user and password work.
</p>
<p>If boolean option <code class="literal">reconnect</code> is given, MySQL
reconnection will be enabled so that if the database conneciton
is dropped, MySQL will attempt to reconnect.
</p>
<p>This store always provides contexts; the boolean storage option
<code class="literal">contexts</code> is not checked.</p>
<p>Examples:</p>
<pre class="programlisting">
/* A new MySQL store */
storage=librdf_new_storage(world, "mysql", "db1",
"new='yes',host='localhost',database='red',user='foo','password='bar'");
/* A different, existing MySQL store db2 in the same database as above */
storage=librdf_new_storage(world, "mysql", "db2",
"host='localhost',database='red',user='foo','password='bar'");
/* An existing MySQL store on a different database server */
storage=librdf_new_storage(world, "mysql", "db3",
"host='db.example.org',database='abc',user='baz','password='blah'");
/* Opening with an options hash */
options=librdf_new_hash(world, NULL);
librdf_hash_from_string(options,
"host='db.example.org',database='abc',user='baz'");
librdf_hash_put_strings(options, "password", user_password);
storage=librdf_new_storage_with_options(world, "mysql", "db4", options);
</pre>
<p>In PHP:</p>
<pre class="programlisting">
# An existing store
$storage=librdf_new_storage($world, 'mysql', 'db4',
"host='127.0.0.1',database='xyz',user='foo',password='blah'");
</pre>
<p>Summary:</p>
<div class="itemizedlist"><ul type="disc">
<li><p>Persistent</p></li>
<li><p>Suitable for very large models</p></li>
<li><p>Indexed but not optimised</p></li>
<li><p>Smaller disk usage than BDB</p></li>
<li><p>Possibility of free text searching</p></li>
<li><p>Contexts always provided</p></li>
</ul></div>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.10</div>
</body>
</html>