<!--$Id: seq_open.so,v 1.7 2004/09/28 15:04:22 bostic Exp $--> <!--Copyright 1997-2004 by Sleepycat Software, Inc.--> <!--All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DbSequence::open</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <h3>DbSequence::open</h3> </td> <td align=right> <a href="../../db43-devel-4.3.21/api_cxx/api_core.html"><img src="../../db43-4.3.21/images/api.gif" alt="API"></a> <a href="../../db43-devel-4.3.21/ref/toc.html"><img src="../../db43-4.3.21/images/ref.gif" alt="Ref"></a></td> </tr></table> <hr size=1 noshade> <tt> <h3><pre> #include <db_cxx.h> <p> int int DbSequence::open(DbTxn *txnid, Dbt *key, u_int32_t flags); <p> int DbSequence::get_dbp(Db **dbp); <p> int DbSequence::get_key(Dbt *key); </pre></h3> <hr size=1 noshade> <h3>Description: DbSequence::open</h3> <p>The DbSequence::open method opens the sequence represented by the <b>key</b>. The key must be compatible with the underlying database specified in the corresponding call to <a href="../../db43-devel-4.3.21/api_c/seq_class.html">db_sequence_create</a>.</p> <h3>Parameters</h3> <dl compact> <dt><b>key</b><dd>The <b>key</b> specifies which record in the database stores the persistent sequence data. <dt><b>flags</b><dd>The <b>flags</b> parameter must be set to 0 or by bitwise inclusively <b>OR</b>'ing together one or more of the following values: <dl compact> <dt><a name="DB_AUTO_COMMIT">DB_AUTO_COMMIT</a><dd>Enclose the DbSequence::open call within a transaction. If the call succeeds, the open operation will be recoverable. If the <a href="../../db43-devel-4.3.21/api_cxx/env_open.html#DB_CREATE">DB_CREATE</a> flag is specified and the call fails, no sequence will have been created. <dt><a name="DB_CREATE">DB_CREATE</a><dd>Create the sequence. If the sequence does not already exist and the DB_CREATE flag is not specified, the DbSequence::open will fail. <dt><a name="DB_EXCL">DB_EXCL</a><dd>Return an error if the sequence already exists. The <a href="../../db43-devel-4.3.21/api_cxx/db_open.html#DB_EXCL">DB_EXCL</a> flag is only meaningful when specified with the <a href="../../db43-devel-4.3.21/api_cxx/env_open.html#DB_CREATE">DB_CREATE</a> flag. <dt><a name="DB_THREAD">DB_THREAD</a><dd>Cause the <a href="../../db43-devel-4.3.21/api_cxx/seq_class.html">DbSequence</a> handle returned by DbSequence::open to be <i>free-threaded</i>; that is, usable by multiple threads within a single address space. </dl> <dt><b>txnid</b><dd>If the operation is to be transaction-protected, (other than by specifying the DB_AUTO_COMMIT flag), the <b>txnid</b> parameter is a transaction handle returned from <a href="../../db43-devel-4.3.21/api_cxx/txn_begin.html">DbEnv::txn_begin</a>; otherwise, NULL. Note that transactionally protected operations on a <a href="../../db43-devel-4.3.21/api_cxx/seq_class.html">DbSequence</a> handle require the <a href="../../db43-devel-4.3.21/api_cxx/seq_class.html">DbSequence</a> handle itself be transactionally protected during its open if the open creates the sequence. </dl> <hr size=1 noshade> <h3>Description: DbSequence::get_dbp</h3> <p>The DbSequence::get_dbp method returns the database handle.</p> <h3>Parameters</h3> <dl compact> <dt><b>dbp</b><dd>The <b>dbp</b> parameter references memory into which a pointer to the database handle is copied. </dl> <p>The DbSequence::get_dbp method may be called at any time during the life of the application.</p> <p>The DbSequence::get_dbp method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </p> <hr size=1 noshade> <h3>Description: DbSequence::get_key</h3> <p>The DbSequence::get_key method returns the key for the sequence.</p> <h3>Parameters</h3> <dl compact> <dt><b>key</b><dd>The <b>key</b> parameter references memory into which a pointer to the key data is copied. </dl> <p>The DbSequence::get_key method may be called at any time during the life of the application.</p> <p>The DbSequence::get_key method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </p> <hr size=1 noshade> <h3>Class</h3> <a href="../../db43-devel-4.3.21/api_cxx/seq_class.html">DbSequence</a> <h3>See Also</h3> <a href="../../db43-devel-4.3.21/api_cxx/seq_list.html">Sequences and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../../db43-devel-4.3.21/api_cxx/api_core.html"><img src="../../db43-4.3.21/images/api.gif" alt="API"></a><a href="../../db43-devel-4.3.21/ref/toc.html"><img src="../../db43-4.3.21/images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1><a href="../../db43-devel-4.3.21/sleepycat/legal.html">Copyright (c) 1996-2004</a> <a href="http://www.sleepycat.com">Sleepycat Software, Inc.</a> - All rights reserved.</font> </body> </html>
