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<p>Library Version 11.2.5.3</p>
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<th colspan="3" align="center">Dbc::del()</th>
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<td width="20%" align="left"><a accesskey="p" href="dbccount.html">Prev</a> </td>
<th width="60%" align="center">Chapter 3.
The Dbc Handle
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<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="dbcdel"></a>Dbc::del()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db_cxx.h>
int
Dbc::del(u_int32_t flags);</pre>
<p>
The <code class="methodname">Dbc::del()</code> method deletes the key/data pair to which the
cursor refers.
</p>
<p>
When called on a cursor opened on a database that has been made into a
secondary index using the
<a class="xref" href="dbassociate.html" title="Db::associate()">Db::associate()</a> method, the
<a class="xref" href="dbdel.html" title="Db::del()">Db::del()</a> method deletes
the key/data pair from the primary database and all secondary indices.
</p>
<p>
The cursor position is unchanged after a delete, and subsequent calls
to cursor functions expecting the cursor to refer to an existing key
will fail.
</p>
<p>
The <code class="methodname">Dbc::del()</code> method will return <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_KEYEMPTY" class="olink">DB_KEYEMPTY</a> if
the element has already been deleted. The <code class="methodname">Dbc::del()</code>
<span>
<span>
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.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp6126480"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6125296"></a>flags</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter must be set to 0
or one of the following values:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p><a id="dbcput_DB_CONSUME"></a>
<code class="literal">DB_CONSUME</code>
</p>
<p>
If the database is of type DB_QUEUE then this flag may be set to force the head of the queue
to move to the first non-deleted item in the queue. Normally this is only done if the
deleted item is exactly at the head when deleted.
</p>
</li>
</ul>
</div>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp6161976"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">Dbc::del()</code> <span>
<span>
method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
exception, encapsulating one of the following non-zero errors, or return one
of the following non-zero errors:
</span>
</span>
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6170152"></a>DB_FOREIGN_CONFLICT</h4>
</div>
</div>
</div>
<p>
A <a class="link" href="dbassociate_foreign.html" title="Db::associate_foreign()">foreign key constraint violation</a>
has occurred. This can be caused by one of two things:
</p>
<div class="orderedlist">
<ol type="1">
<li>
<p>
An attempt was made to add a record to a
constrained database, and the key used for that
record does not exist in the foreign key
database.
</p>
</li>
<li>
<p>
<a class="link" href="dbassociate_foreign.html#associate_foreign_DB_FOREIGN_ABORT">DB_FOREIGN_ABORT</a>
was declared for a foreign key database, and then
subsequently a record was deleted from the
foreign key database without first removing it
from the constrained secondary database.
</p>
</li>
</ol>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6145528"></a><span>DbDeadlockException or </span>DB_LOCK_DEADLOCK</h4>
</div>
</div>
</div>
<p>
A transactional database environment operation was selected to resolve
a deadlock.
</p>
<p>
<a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
your Berkeley DB API is configured to throw exceptions.
Otherwise, <code class="literal">DB_LOCK_DEADLOCK</code> is returned.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6162944"></a><span>DbLockNotGrantedException or </span>DB_LOCK_NOTGRANTED</h4>
</div>
</div>
</div>
<p>
A Berkeley DB Concurrent Data Store database environment configured
for lock timeouts was unable to grant a lock in the allowed time.
</p>
<p>
You attempted to open a database handle that is configured
for no waiting exclusive locking, but the exclusive lock could not be
immediately obtained. See
<a class="xref" href="dbset_lk_exclusive.html" title="Db::set_lk_exclusive()">Db::set_lk_exclusive()</a>
for more information.
</p>
<p>
<a class="xref" href="dblocknotgranted.html" title="DbLockNotGrantedException">DbLockNotGrantedException</a> is thrown if
your Berkeley DB API is configured to throw exceptions.
Otherwise, <code class="literal">DB_LOCK_NOTGRANTED</code> is returned.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6163176"></a> <span>DbRepHandleDeadException or</span> DB_REP_HANDLE_DEAD</h4>
</div>
</div>
</div>
<p>
When a client synchronizes with the master, it is possible for committed
transactions to be rolled back. This invalidates all the database and cursor
handles opened in the replication environment. Once this occurs, an attempt to use
such a handle will
<span>
throw a <a class="xref" href="dbrephandledead.html" title="DbRepHandleDeadException">DbRepHandleDeadException</a> (if
your application is configured to throw exceptions), or
</span>
return <code class="literal">DB_REP_HANDLE_DEAD</code>.
The application will need to discard the handle and open a new one in order to
continue processing.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6174240"></a><span>DbDeadlockException or </span>DB_REP_LOCKOUT</h4>
</div>
</div>
</div>
<p>
The operation was blocked by client/master synchronization.
</p>
<p>
<a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
your Berkeley DB API is configured to throw exceptions.
Otherwise, <code class="literal">DB_REP_LOCKOUT</code> is returned.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6175320"></a>DB_SECONDARY_BAD</h4>
</div>
</div>
</div>
<p>
A secondary index references a nonexistent primary key.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6155448"></a>EACCES</h4>
</div>
</div>
</div>
<p>
An attempt was made to modify a read-only database.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6155856"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
If the cursor has not been initialized; or if an invalid flag value or parameter was specified.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp6156312"></a>EPERM</h4>
</div>
</div>
</div>
<p>
Write attempted on read-only cursor when the
<a class="link" href="envopen.html#envopen_DB_INIT_CDB">DB_INIT_CDB</a>
flag was specified to <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a>.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp6161760"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="dbc.html" title="Chapter 3. The Dbc Handle">Dbc</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp6159632"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="dbc.html#dbclist" title="Database Cursors and Related Methods">Database Cursors and Related Methods</a>
</p>
</div>
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<a accesskey="u" href="dbc.html">Up</a>
</td>
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</tr>
<tr>
<td width="40%" align="left" valign="top">Dbc::count() </td>
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