<!--$Id: db_cursor.html,v 1.1.1.1 2003/02/15 04:55:50 zarzycki Exp $--> <!--Copyright 1997-2002 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> <h1>Db.cursor</h1> </td> <td align=right> <a href="../api_java/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../reftoc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <hr size=1 noshade> <tt> <h3><pre> import com.sleepycat.db.*; <p> public Dbc cursor(DbTxn txnid, int flags) throws DbException; </pre></h3> <h1>Description</h1> <p>The Db.cursor method creates a cursor. <p>If the operation is to be transaction-protected, the <b>txnid</b> parameter is a transaction handle returned from <a href="../api_java/txn_begin.html">DbEnv.txn_begin</a>; otherwise, null. <p>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. <p>The <b>flags</b> value 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.DB_DIRTY_READ">Db.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_java/db_open.html#DB_DIRTY_READ">Db.DB_DIRTY_READ</a> flag was not specified when the underlying database was opened. <p><dt><a name="Db.DB_WRITECURSOR">Db.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_java/env_open.html#DB_INIT_CDB">Db.DB_INIT_CDB</a> flag. </dl> <p>The Db.cursor method throws an exception that encapsulates a non-zero error value on failure. <h1>Errors</h1> <p>The Db.cursor method may fail and throw an exception encapsulating a non-zero error for the following conditions: <p><dl compact> <p><dt>EINVAL<dd>An invalid flag value or parameter was specified. </dl> <p>The Db.cursor method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the Db.cursor method may fail and throw a <a href="../api_java/runrec_class.html">DbRunRecoveryException</a>, in which case all subsequent Berkeley DB calls will fail in the same way. <h1>Class</h1> <a href="../api_java/dbc_class.html">Dbc</a> <h1>See Also</h1> <a href="../api_java/dbc_list.html">Database Cursors and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../api_java/c_index.html"><img src="../images/api.gif" alt="API"></a><a href="../reftoc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> </body> </html>