<?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>Release 3.0: the Db class for C++ and Java</title> <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" /> <link rel="up" href="upgrade_3_0_toc.html" title="Chapter 33. Upgrading Berkeley DB 2.X applications to Berkeley DB 3.0" /> <link rel="prev" href="upgrade_3_0_dbenv_cxx.html" title="Release 3.0: the DbEnv class for C++ and Java" /> <link rel="next" href="upgrade_3_0_cxx.html" title="Release 3.0: additional C++ changes" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">Release 3.0: the Db class for C++ and Java</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="upgrade_3_0_dbenv_cxx.html">Prev</a> </td> <th width="60%" align="center">Chapter 33. Upgrading Berkeley DB 2.X applications to Berkeley DB 3.0</th> <td width="20%" align="right"> <a accesskey="n" href="upgrade_3_0_cxx.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="upgrade_3_0_db_cxx"></a>Release 3.0: the Db class for C++ and Java</h2> </div> </div> </div> <p>The static Db::open method and the DbInfo class have been removed in the Berkeley DB 3.0 release. The way to open a database file is to use the new Db constructor with two arguments, followed by set_XXX methods to configure the Db object, and finally a call to the new (nonstatic) Db::open(). In comparing the Berkeley DB 3.0 release open method with the 2.X static open method, the second argument is new. It is a database name, which can be null. The DbEnv argument has been removed, as the environment is now specified in the constructor. The open method no longer returns a Db, since it operates on one.</p> <p>Here's a C++ example opening a Berkeley DB database using the 2.X interface:</p> <pre class="programlisting">// Note: by default, errors are thrown as exceptions Db *table; Db::open("lookup.db", DB_BTREE, DB_CREATE, 0644, dbenv, 0, &table);</pre> <p>In the Berkeley DB 3.0 release, this code would be written as:</p> <pre class="programlisting">// Note: by default, errors are thrown as exceptions Db *table = new Db(dbenv, 0); table->open("lookup.db", NULL, DB_BTREE, DB_CREATE, 0644);</pre> <p>Here's a Java example opening a Berkeley DB database using the 2.X interface:</p> <pre class="programlisting">// Note: errors are thrown as exceptions Db table = Db.open("lookup.db", Db.DB_BTREE, Db.DB_CREATE, 0644, dbenv, 0);</pre> <p>In the Berkeley DB 3.0 release, this code would be written as:</p> <pre class="programlisting">// Note: errors are thrown as exceptions Db table = new Db(dbenv, 0); table.open("lookup.db", null, Db.DB_BTREE, Db.DB_CREATE, 0644);</pre> <p>Note that if the dbenv argument is null, the database will not exist within an environment.</p> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="upgrade_3_0_dbenv_cxx.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="upgrade_3_0_toc.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="upgrade_3_0_cxx.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Release 3.0: the DbEnv class for C++ and Java </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Release 3.0: additional C++ changes</td> </tr> </table> </div> </body> </html>