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<!--$Id: db_cursor.so,v 10.25 2000/07/11 19:11:25 bostic Exp $-->
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<h1>DB->cursor</h1>
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<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>
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