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<th colspan="3" align="center">db_create</th>
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The DB Handle
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<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="dbcreate"></a>db_create</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db.h>
int db_create(DB **dbp, DB_ENV *dbenv, u_int32_t flags); </pre>
<p>
The <code class="function">db_create()</code> function creates a <a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>
structure that is the handle for a Berkeley DB database. This function allocates memory for the
structure, returning a pointer to the structure in the memory to which
<span class="bold"><strong>dbp</strong></span> refers. To release the allocated memory and
discard the handle, call the <a class="xref" href="dbclose.html" title="DB->close()">DB->close()</a>,
<a class="xref" href="dbremove.html" title="DB->remove()">DB->remove()</a>,
<a class="xref" href="dbrename.html" title="DB->rename()">DB->rename()</a>, or
<a class="xref" href="dbverify.html" title="DB->verify()">DB->verify()</a> methods.
</p>
<p>
DB handles are free-threaded if the
<a class="link" href="envopen.html#envopen_DB_THREAD">DB_THREAD</a> flag is specified to
the <a class="xref" href="dbopen.html" title="DB->open()">DB->open()</a> method when the database is opened or
if the database environment in which the database is opened is free-threaded. The handle
should not be closed while any other handle that refers to the database is in use; for
example, database handles must not be closed while cursor handles into the database remain
open, or transactions that include operations on the database have not yet been committed
or aborted. Once the <a class="xref" href="dbclose.html" title="DB->close()">DB->close()</a>,
<a class="xref" href="dbremove.html" title="DB->remove()">DB->remove()</a>,
<a class="xref" href="dbrename.html" title="DB->rename()">DB->rename()</a>, or
<a class="xref" href="dbverify.html" title="DB->verify()">DB->verify()</a>
methods are called, the handle may not be accessed again, regardless of the method's return.
</p>
<p>
The DB handle contains a special field, <code class="literal">app_private</code>,
which is declared as type <code class="literal">void *</code>. This field is provided for the use
of the application program. It is initialized to NULL and is not further used by
Berkeley DB in any way.
</p>
<p>
The <code class="literal">db_create</code> function returns a non-zero error value on failure
and 0 on success.
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp49533896"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp49591080"></a>dbp</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>dbp</strong></span> parameter references the
memory into which the returned structure pointer is stored.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp49626816"></a>dbenv</h4>
</div>
</div>
</div>
<p>
<span>If the <span class="bold"><strong>dbenv</strong></span> parameter is NULL,</span>
the database is standalone; that is, it is not part of any Berkeley DB
environment.
</p>
<p>
<span>
If the <span class="bold"><strong>dbenv</strong></span> parameter is not NULL,
</span>
the database is created within the specified Berkeley DB environment.
The database access methods automatically make calls to the other
subsystems in Berkeley DB, based on the enclosing environment. For
example, if the environment has been configured to use locking, the
access methods will automatically acquire the correct locks when
reading and writing pages of the database.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp49655968"></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>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp49626152"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="function">db_create()</code> function may fail and return one of the following non-zero
errors:
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp49482344"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
An invalid flag value or parameter was specified.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp49490848"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp49648312"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a>
</p>
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