<!--$Id: db_cursor.html,v 1.2 2004/03/30 01:21:42 jtownsen Exp $--> <!--Copyright 1997-2003 by Sleepycat Software, Inc.--> <!--All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DB->cursor</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <a name="2"><!--meow--></a> <table width="100%"><tr valign=top> <td> <h3>DB->cursor</h3> </td> <td align=right> <a href="../api_c/api_index.html"><img src="../images/api.gif" alt="API"></a> <a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <hr size=1 noshade> <tt> <h3><pre> #include <db.h> <p> int DB->cursor(DB *db, DB_TXN *txnid, DBC **cursorp, u_int32_t flags); </pre></h3> <hr size=1 noshade> <h3>Description: DB->cursor</h3> The DB->cursor method returns a created database cursor. <p>The DB->cursor method returns a non-zero error value on failure and 0 on success. </p> <h3>Parameters</h3> <p><dl compact> <p><dt><b>cursorp</b><dd> The <b>cursorp</b> parameter references memory into which a pointer to the allocated cursor is copied. <p><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: <p><dl compact> <p><dt><a name="DB_DIRTY_READ">DB_DIRTY_READ</a><dd>All read operations performed by the cursor may return modified but not yet committed data. Silently ignored if the <a href="../api_c/db_open.html#DB_DIRTY_READ">DB_DIRTY_READ</a> flag was not specified when the underlying database was opened. <p><dt><a name="DB_WRITECURSOR">DB_WRITECURSOR</a><dd>Specify that the cursor will be used to update the database. The underlying database environment must have been opened using the <a href="../api_c/env_open.html#DB_INIT_CDB">DB_INIT_CDB</a> flag. </dl> <p><dt><b>txnid</b><dd> If the operation is to be transaction-protected, the <b>txnid</b> parameter is a transaction handle returned from <a href="../api_c/txn_begin.html">DB_ENV->txn_begin</a>; otherwise, NULL. To transaction-protect cursor operations, cursors must be opened and closed within the context of a transaction, and the <b>txnid</b> parameter specifies the transaction context in which the cursor may be used. </dl> <h3>Errors</h3> <p>The DB->cursor method may fail and return one of the following non-zero errors:</p> <p><dl compact> <p><dt>DB_REP_HANDLE_DEAD<dd>The database handle has been invalidated because a replication election unrolled a committed transaction. </dl> <p><dl compact> <p><dt>EINVAL<dd>An invalid flag value or parameter was specified. </dl> <hr size=1 noshade> <h3>Class</h3> <a href="../api_c/dbc_class.html">DBC</a> <h3>See Also</h3> <a href="../api_c/dbc_list.html">Database Cursors and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../api_c/api_index.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1><a href="../sleepycat/legal.html">Copyright (c) 1996-2003</a> <a href="http://www.sleepycat.com">Sleepycat Software, Inc.</a> - All rights reserved.</font> </body> </html>