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<p class="banner">SOCI - The C++ Database Access Library</p>
<h2>Connections and simple queries</h2>
<h3>Connecting to the database</h3>
<p>The class <code>Session</code> encapsulates the database connection
and other backend-related details, which are common to all the
statements
that will be later executed. Its constructor expects two parameters:
the requested backend factory object and the generic connection string,
which meaning is backend-dependent.</p>
<p>Example:</p>
<pre class="example">
Session sql(oracle, "service=orcl user=scott password=tiger");
</pre>
<p>Another example might be:</p>
<pre class="example">
Session sql(postgresql, "dbname=mydb");
</pre>
<p>Above, the <code>sql</code> object is a local (automatic) object
that encapsulates the connection.</p>
<p>The <code>Session</code> constructor either connects successfully, or
throws the exception.</p>
<p>It is possible to have many active <code>Session</code>s at the same
time, even using different backends.</p>
<div class="note">
<p><span class="note">Portability note:</span></p>
<p>The following backend factories are currently available:</p>
<ul>
<li><code><a href="backends/mysql.html">mysql</a></code> (requires <code>#include "soci-mysql.h"</code>)</li>
<li><code><a href="backends/oracle.html">oracle</a></code> (requires <code>#include "soci-oracle.h"</code>)</li>
<li><code><a href="backends/postgresql.html">postgresql</a></code> (requires <code>#include "soci-postgresql.h"</code>)</li>
<li><code><a href="backends/sqlite3.html">sqlite3</a></code> (requires <code>#include "soci-sqlite3.h"</code>)</li>
<li><code><a href="backends/odbc.html">odbc</a></code> (requires <code>#include "soci-odbc.h"</code>)</li>
<li><code><a href="backends/firebird.html">firebird</a></code> (requires <code>#include "soci-firebird.h"</code>)</li>
</ul>
</div>
<h3>Simple SQL statements</h3>
<p>In many cases, the SQL query is intended to be executed only once,
which means that statement parsing and execution can go together.
The <code>Session</code> class provides a special <code>once</code>
member, which triggers parsing and execution of such one-time
statements:</p>
<pre class="example">
sql.once << "drop table persons";
</pre>
<p>For shorter syntax, the following form is also allowed:</p>
<pre class="example">
sql << "drop table persons";
</pre>
<p>The IOStream-like interface is exactly what it looks like, so that
the
statement text can be composed of many parts, involving anything that
is <i>streamable</i> (including custom classes, if they have
appropriate <code>operator<<</code>):</p>
<pre class="example">
string tableName = "persons";
sql << "drop table " << tableName;
int id = 123;
sql << "delete from companies where id = " << id;
</pre>
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<p class="copyright">Copyright © 2004-2006 Maciej Sobczak, Stephen Hutton</p>
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