<!--$Id: db_cursor.so,v 10.25 2000/07/11 19:11:25 bostic Exp $--> <!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> <!--All rights reserved.--> <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><tr valign=top> <td> <h1>DB->cursor</h1> </td> <td width="1%"> <a href="../api_c/c_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> <h1>Description</h1> <p>The DB->cursor function creates a cursor and copies a pointer to it into the memory referenced by <b>cursorp</b>. <p>If the file is being accessed under transaction protection, the <b>txnid</b> parameter is a transaction ID returned from <a href="../api_c/txn_begin.html">txn_begin</a>, otherwise, NULL. <p>If transaction protection is enabled, 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_WRITECURSOR">DB_WRITECURSOR</a><dd>Specify that the cursor will be used to update the database. This flag should <b>only</b> be set when the <a href="../api_c/env_open.html#DB_INIT_CDB">DB_INIT_CDB</a> flag was specified to <a href="../api_c/env_open.html">DBENV->open</a>. </dl> <p>The DB->cursor function returns a non-zero error value on failure and 0 on success. <h1>Errors</h1> <p>The DB->cursor function may fail and return 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 function may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the DB->cursor function may fail and return <a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a>, in which case all subsequent Berkeley DB calls will fail in the same way. <h1>See Also</h1> <a href="../api_c/db_create.html">db_create</a>, <a href="../api_c/db_close.html">DB->close</a>, <a href="../api_c/db_cursor.html">DB->cursor</a>, <a href="../api_c/db_del.html">DB->del</a>, <a href="../api_c/db_err.html">DB->err</a>, <a href="../api_c/db_fd.html">DB->fd</a>, <a href="../api_c/db_get.html">DB->get</a>, <a href="../api_c/db_get_byteswapped.html">DB->get_byteswapped</a>, <a href="../api_c/db_get_type.html">DB->get_type</a>, <a href="../api_c/db_join.html">DB->join</a>, <a href="../api_c/db_key_range.html">DB->key_range</a>, <a href="../api_c/db_open.html">DB->open</a>, <a href="../api_c/db_put.html">DB->put</a>, <a href="../api_c/db_remove.html">DB->remove</a>, <a href="../api_c/db_set_bt_compare.html">DB->set_bt_compare</a>, <a href="../api_c/db_set_bt_minkey.html">DB->set_bt_minkey</a>, <a href="../api_c/db_set_bt_prefix.html">DB->set_bt_prefix</a>, <a href="../api_c/db_set_cachesize.html">DB->set_cachesize</a>, <a href="../api_c/db_set_dup_compare.html">DB->set_dup_compare</a>, <a href="../api_c/db_set_errcall.html">DB->set_errcall</a>, <a href="../api_c/db_set_errfile.html">DB->set_errfile</a>, <a href="../api_c/db_set_errpfx.html">DB->set_errpfx</a>, <a href="../api_c/db_set_flags.html">DB->set_flags</a>, <a href="../api_c/db_set_h_ffactor.html">DB->set_h_ffactor</a>, <a href="../api_c/db_set_h_hash.html">DB->set_h_hash</a>, <a href="../api_c/db_set_h_nelem.html">DB->set_h_nelem</a>, <a href="../api_c/db_set_lorder.html">DB->set_lorder</a>, <a href="../api_c/db_set_malloc.html">DB->set_malloc</a>, <a href="../api_c/db_set_pagesize.html">DB->set_pagesize</a>, <a href="../api_c/db_set_paniccall.html">DB->set_paniccall</a>, <a href="../api_c/db_set_q_extentsize.html">DB->set_q_extentsize</a>, <a href="../api_c/db_set_realloc.html">DB->set_realloc</a>, <a href="../api_c/db_set_re_delim.html">DB->set_re_delim</a>, <a href="../api_c/db_set_re_len.html">DB->set_re_len</a>, <a href="../api_c/db_set_re_pad.html">DB->set_re_pad</a>, <a href="../api_c/db_set_re_source.html">DB->set_re_source</a>, <a href="../api_c/db_stat.html">DB->stat</a>, <a href="../api_c/db_sync.html">DB->sync</a>, <a href="../api_c/db_upgrade.html">DB->upgrade</a> and <a href="../api_c/db_verify.html">DB->verify</a>. </tt> <table><tr><td><br></td><td width="1%"> <a href="../api_c/c_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="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> </body> </html>