1<?xml version="1.0" encoding="UTF-8" standalone="no"?>
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml">
4  <head>
5    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
6    <title>Error Returns</title>
7    <link rel="stylesheet" href="gettingStarted.css" type="text/css" />
8    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
9    <link rel="start" href="index.html" title="Getting Started with Berkeley DB" />
10    <link rel="up" href="introduction.html" title="Chapter��1.��Introduction to Berkeley DB" />
11    <link rel="prev" href="coreExceptions.html" title="Exception Handling" />
12    <link rel="next" href="gettingit.html" title="Getting and Using DB" />
13  </head>
14  <body>
15    <div class="navheader">
16      <table width="100%" summary="Navigation header">
17        <tr>
18          <th colspan="3" align="center">Error Returns</th>
19        </tr>
20        <tr>
21          <td width="20%" align="left"><a accesskey="p" href="coreExceptions.html">Prev</a>��</td>
22          <th width="60%" align="center">Chapter��1.��Introduction to Berkeley DB </th>
23          <td width="20%" align="right">��<a accesskey="n" href="gettingit.html">Next</a></td>
24        </tr>
25      </table>
26      <hr />
27    </div>
28    <div class="sect1" lang="en" xml:lang="en">
29      <div class="titlepage">
30        <div>
31          <div>
32            <h2 class="title" style="clear: both"><a id="returns"></a>Error Returns</h2>
33          </div>
34        </div>
35      </div>
36      <p>
37        <span>In addition to exceptions, the</span>
38        
39        DB interfaces always return a value of 0 on success. If the
40        operation does not succeed for any reason, the return value will be
41        non-zero.
42    </p>
43      <p>
44        If a system error occurred (for example, DB ran out of disk
45        space, or permission to access a file was denied, or an illegal argument
46        was specified to one of the interfaces), DB returns an
47        <code class="literal">errno</code>
48        value. All of the possible values of <code class="literal">errno</code> are greater than 0.
49    </p>
50      <p>
51        If the operation did not fail due to a system error, but was not
52        successful either, DB returns a special error value. For
53        example, if you tried to retrieve data from the database and the
54        record for which you are searching does not exist, DB would return
55        <code class="literal">DB_NOTFOUND</code>, a special error value that means the requested
56        key does not appear in the database. All of the possible special error
57        values are less than 0.
58    </p>
59    </div>
60    <div class="navfooter">
61      <hr />
62      <table width="100%" summary="Navigation footer">
63        <tr>
64          <td width="40%" align="left"><a accesskey="p" href="coreExceptions.html">Prev</a>��</td>
65          <td width="20%" align="center">
66            <a accesskey="u" href="introduction.html">Up</a>
67          </td>
68          <td width="40%" align="right">��<a accesskey="n" href="gettingit.html">Next</a></td>
69        </tr>
70        <tr>
71          <td width="40%" align="left" valign="top">Exception Handling��</td>
72          <td width="20%" align="center">
73            <a accesskey="h" href="index.html">Home</a>
74          </td>
75          <td width="40%" align="right" valign="top">��Getting and Using DB </td>
76        </tr>
77      </table>
78    </div>
79  </body>
80</html>
81