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231 lines
8.7 KiB
HTML
231 lines
8.7 KiB
HTML
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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>Dbc::dup()</title>
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<link rel="stylesheet" href="apiReference.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
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<link rel="up" href="dbc.html" title="Chapter 3. The Dbc Handle" />
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<link rel="prev" href="dbcdel.html" title="Dbc::del()" />
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<link rel="next" href="dbcget.html" title="Dbc::get()" />
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</head>
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<body>
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<div xmlns="" class="navheader">
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<div class="libver">
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<p>Library Version 11.2.5.2</p>
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</div>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">Dbc::dup()</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="dbcdel.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 3.
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The Dbc Handle
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="dbcget.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="dbcdup"></a>Dbc::dup()</h2>
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</div>
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</div>
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</div>
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<pre class="programlisting">#include <db_cxx.h>
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int
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Dbc::dup(Dbc **cursorp, u_int32_t flags);</pre>
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<p>
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The <code class="methodname">Dbc::dup()</code> method creates a new cursor that uses the same
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transaction and locker ID as the original cursor. This is useful when
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an application is using locking and requires two or more cursors in
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the same thread of control.
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</p>
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<p>
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The <code class="methodname">Dbc::dup()</code> <span>
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<span>
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method either returns a non-zero error value or throws an
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exception that encapsulates a non-zero error value on
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failure, and returns 0 on success.
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</span>
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</span>
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</p>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="id3605130"></a>Parameters</h3>
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</div>
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</div>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="id3605119"></a>cursorp</h4>
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</div>
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</div>
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</div>
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<p>
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The <code class="methodname">Dbc::dup()</code> method
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returns the newly created cursor in
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<span class="bold"><strong>cursorp</strong></span>.
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="id3604855"></a>flags</h4>
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</div>
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</div>
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</div>
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<p>
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The <span class="bold"><strong>flags</strong></span> parameter must be set to 0
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or the following flag:
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</p>
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<div class="itemizedlist">
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<ul type="disc">
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<li>
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<p><a id="dup_DB_POSITION"></a>
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<code class="literal">DB_POSITION</code>
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</p>
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<p>
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The newly created cursor is initialized to refer to the same position
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in the database as the original cursor (if any) and hold the same
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locks (if any). If the DB_POSITION flag is not specified, or the
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original cursor does not hold a database position and locks, the
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created cursor is uninitialized and will behave like a cursor newly
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created using the <a class="xref" href="dbcursor.html" title="Db::cursor()">Db::cursor()</a>
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method.
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</p>
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</li>
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</ul>
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</div>
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</div>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="id3605243"></a>Errors</h3>
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</div>
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</div>
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</div>
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<p>
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The <code class="methodname">Dbc::dup()</code> <span>
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<span>
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method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
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exception, encapsulating one of the following non-zero errors, or return one
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of the following non-zero errors:
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</span>
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</span>
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</p>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="id3605376"></a> <span>DbRepHandleDeadException or</span> DB_REP_HANDLE_DEAD</h4>
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</div>
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</div>
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</div>
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<p>
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When a client synchronizes with the master, it is possible for committed
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transactions to be rolled back. This invalidates all the database and cursor
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handles opened in the replication environment. Once this occurs, an attempt to use
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such a handle will
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<span>
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throw a <a class="xref" href="dbrephandledead.html" title="DbRepHandleDeadException">DbRepHandleDeadException</a> (if
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your application is configured to throw exceptions), or
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</span>
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return <code class="literal">DB_REP_HANDLE_DEAD</code>.
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The application will need to discard the handle and open a new one in order to
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continue processing.
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="id3604872"></a><span>DbDeadlockException or </span>DB_REP_LOCKOUT</h4>
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</div>
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</div>
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</div>
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<p>
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The operation was blocked by client/master synchronization.
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</p>
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<p>
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<a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
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your Berkeley DB API is configured to throw exceptions.
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Otherwise, <code class="literal">DB_REP_LOCKOUT</code> is returned.
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</p>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h4 class="title"><a id="id3605256"></a>EINVAL</h4>
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</div>
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</div>
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</div>
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<p>
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An invalid flag value or parameter was specified.
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</p>
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</div>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="id3605224"></a>Class</h3>
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</div>
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</div>
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</div>
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<p>
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<a class="link" href="dbc.html" title="Chapter 3. The Dbc Handle">Dbc</a>
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</p>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h3 class="title"><a id="id3604998"></a>See Also</h3>
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</div>
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</div>
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</div>
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<p>
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<a class="xref" href="dbc.html#dbclist" title="Database Cursors and Related Methods">Database Cursors and Related Methods</a>
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</p>
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</div>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="dbcdel.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="dbc.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="dbcget.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">Dbc::del() </td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> Dbc::get()</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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