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<th colspan="3" align="center">DB->truncate()</th>
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<h2 class="title" style="clear: both"><a id="dbtruncate"></a>DB->truncate()</h2>
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<pre class="programlisting">#include <db.h>
int
DB->truncate(DB *db,
DB_TXN *txnid, u_int32_t *countp, u_int32_t flags); </pre>
<p>
The <code class="methodname">DB->truncate()</code> method empties the database, discarding all
records it contains. The number of records discarded from the
database is returned in <span class="bold"><strong>countp</strong></span>.
</p>
<p>
When called on a database configured with secondary indices using the
<a class="xref" href="dbassociate.html" title="DB->associate()">DB->associate()</a>
method, the <code class="methodname">DB->truncate()</code> method truncates the primary database and
all secondary indices. A count of the records discarded from the
primary database is returned.
</p>
<p>
It is an error to call the <code class="methodname">DB->truncate()</code> method on a database with
open cursors.
</p>
<p>
The <code class="methodname">DB->truncate()</code> <span>
<span>
method returns a non-zero error value on failure and 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<div>
<h3 class="title"><a id="id1651900"></a>Parameters</h3>
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<div class="sect3" lang="en" xml:lang="en">
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<div>
<div>
<h4 class="title"><a id="id1652084"></a>countp</h4>
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<p>
The <span class="bold"><strong>countp</strong></span> parameter references
memory into which the number of records discarded from the database
is copied.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id1652205"></a>flags</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter is currently
unused, and must be set to 0.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
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<div>
<h4 class="title"><a id="id1652137"></a>txnid</h4>
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<p>
If the operation is part of an application-specified transaction, the
<span class="bold"><strong>txnid</strong></span> parameter is a transaction
handle returned from <a class="xref" href="txnbegin.html" title="DB_ENV->txn_begin()">DB_ENV->txn_begin()</a>; if the
operation is part of a Berkeley DB Concurrent Data Store group, the
<span class="bold"><strong>txnid</strong></span> parameter is a handle returned
from <a class="xref" href="envcdsgroup_begin.html" title="DB_ENV->cdsgroup_begin()">DB_ENV->cdsgroup_begin()</a>;
otherwise NULL. If no transaction handle is specified, but the
operation occurs in a transactional database, the operation will be
implicitly transaction protected.
</p>
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<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id1652078"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DB->truncate()</code> <span>
<span>
method may fail and 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="id1652085"></a>DB_LOCK_DEADLOCK</h4>
</div>
</div>
</div>
<p>
A transactional database environment operation was selected to resolve
a deadlock.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id1652199"></a>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>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id1652118"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
If there are open cursors in the database; or if an invalid flag value or parameter was specified.
</p>
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<div class="sect2" lang="en" xml:lang="en">
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<h3 class="title"><a id="id1652120"></a>Class</h3>
</div>
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<p>
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>
</p>
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<h3 class="title"><a id="id1652141"></a>See Also</h3>
</div>
</div>
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<p>
<a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a>
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