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<h2 class="title" style="clear: both"><a id="coreExceptions"></a>Exception Handling</h2>
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<p>
Before continuing, it is useful to spend a few moments on exception
handling in DB with the
<span>C++ API</span>.
</p>
<p>
<span>By default, most</span>
DB methods throw
<tt class="classname">DbException</tt>
in the event of a serious error.
<span>
However, be aware that
<tt class="classname">DbException</tt> does not inherit from
<tt class="classname">std::exception</tt> so your <tt class="literal">try</tt>
blocks should catch both types of exceptions. For example:
</span>
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<a id="cxx_intro1"></a>
<pre class="programlisting">#include <db_cxx.h>
...
try
{
// DB and other code goes here
}
catch(DbException &e)
{
// DB error handling goes here
}
catch(std::exception &e)
{
// All other error handling goes here
} </pre>
<p>
You can obtain the DB error number for a
<tt class="classname">DbException</tt>
by using
<span>
<tt class="methodname">DbException::get_errno()</tt>.
You can also obtain the informational message associated with that error
number using <tt class="methodname">DbException::what()</tt>.
</span>
</p>
<p>
If for some reason you do not want to manage
<tt class="classname">DbException</tt> objects in your
<tt class="literal">try</tt> blocks, you can configure DB to suppress them
by setting <tt class="literal">DB_CXX_NO_EXCEPTIONS</tt> for your database and
environment handles. In this event, you must manage your DB error
conditions using the integer value returned by all DB methods. Be
aware that this manual assumes that you want to manage your error
conditions using <tt class="classname">DbException</tt> objects.
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