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>DBcursor->count()</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C API Reference" /> 10 <link rel="up" href="dbc.html" title="Chapter��3.�� The DBcursor Handle" /> 11 <link rel="prev" href="dbccmp.html" title="DBcursor->cmp()" /> 12 <link rel="next" href="dbcdel.html" title="DBcursor->del()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DBcursor->count()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="dbccmp.html">Prev</a>��</td> 22 <th width="60%" align="center">Chapter��3.�� 23 The DBcursor Handle 24 </th> 25 <td width="20%" align="right">��<a accesskey="n" href="dbcdel.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="sect1" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title" style="clear: both"><a id="dbccount"></a>DBcursor->count()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db.h> 39 40int 41DBcursor->count(DBC *DBcursor, db_recno_t *countp, u_int32_t flags); </pre> 42 <p> 43 The <code class="methodname">DBcursor->count()</code> method returns a count of the number of data 44 items for the key to which the cursor refers. 45 </p> 46 <p> 47 The <code class="methodname">DBcursor->count()</code> <span> 48 <span> 49 method returns a non-zero error value on failure and 0 on success. 50 </span> 51 52 </span> 53 </p> 54 <div class="sect2" lang="en" xml:lang="en"> 55 <div class="titlepage"> 56 <div> 57 <div> 58 <h3 class="title"><a id="id1653961"></a>Parameters</h3> 59 </div> 60 </div> 61 </div> 62 <div class="sect3" lang="en" xml:lang="en"> 63 <div class="titlepage"> 64 <div> 65 <div> 66 <h4 class="title"><a id="id1654018"></a>countp</h4> 67 </div> 68 </div> 69 </div> 70 <p> 71 The <span class="bold"><strong>countp</strong></span> parameter references 72 memory into which the count of the number of duplicate data items is 73 copied. 74 </p> 75 </div> 76 <div class="sect3" lang="en" xml:lang="en"> 77 <div class="titlepage"> 78 <div> 79 <div> 80 <h4 class="title"><a id="id1654137"></a>flags</h4> 81 </div> 82 </div> 83 </div> 84 <p> 85 The <span class="bold"><strong>flags</strong></span> parameter is currently 86 unused, and must be set to 0. 87 </p> 88 </div> 89 </div> 90 <div class="sect2" lang="en" xml:lang="en"> 91 <div class="titlepage"> 92 <div> 93 <div> 94 <h3 class="title"><a id="id1654152"></a>Errors</h3> 95 </div> 96 </div> 97 </div> 98 <p> 99 The <code class="methodname">DBcursor->count()</code> <span> 100 <span> 101 method may fail and return one of the following non-zero errors: 102 </span> 103 104 </span> 105 </p> 106 <div class="sect3" lang="en" xml:lang="en"> 107 <div class="titlepage"> 108 <div> 109 <div> 110 <h4 class="title"><a id="id1654028"></a> DB_REP_HANDLE_DEAD</h4> 111 </div> 112 </div> 113 </div> 114 <p> 115 When a client synchronizes with the master, it is possible for committed 116 transactions to be rolled back. This invalidates all the database and cursor 117 handles opened in the replication environment. Once this occurs, an attempt to use 118 such a handle will 119 120 return <code class="literal">DB_REP_HANDLE_DEAD</code>. 121 The application will need to discard the handle and open a new one in order to 122 continue processing. 123 </p> 124 </div> 125 <div class="sect3" lang="en" xml:lang="en"> 126 <div class="titlepage"> 127 <div> 128 <div> 129 <h4 class="title"><a id="id1654105"></a>DB_REP_LOCKOUT</h4> 130 </div> 131 </div> 132 </div> 133 <p> 134 The operation was blocked by client/master synchronization. 135 </p> 136 </div> 137 <div class="sect3" lang="en" xml:lang="en"> 138 <div class="titlepage"> 139 <div> 140 <div> 141 <h4 class="title"><a id="id1654118"></a>EINVAL</h4> 142 </div> 143 </div> 144 </div> 145 <p> 146 If the cursor has not been initialized; or if an invalid flag value or parameter was specified. 147 </p> 148 </div> 149 </div> 150 <div class="sect2" lang="en" xml:lang="en"> 151 <div class="titlepage"> 152 <div> 153 <div> 154 <h3 class="title"><a id="id1654125"></a>Class</h3> 155 </div> 156 </div> 157 </div> 158 <p> 159 <a class="link" href="dbc.html" title="Chapter��3.�� The DBcursor Handle">DBcursor</a> 160 </p> 161 </div> 162 <div class="sect2" lang="en" xml:lang="en"> 163 <div class="titlepage"> 164 <div> 165 <div> 166 <h3 class="title"><a id="id1654058"></a>See Also</h3> 167 </div> 168 </div> 169 </div> 170 <p> 171 <a class="xref" href="dbc.html#dbclist" title="Database Cursors and Related Methods">Database Cursors and Related Methods</a> 172 </p> 173 </div> 174 </div> 175 <div class="navfooter"> 176 <hr /> 177 <table width="100%" summary="Navigation footer"> 178 <tr> 179 <td width="40%" align="left"><a accesskey="p" href="dbccmp.html">Prev</a>��</td> 180 <td width="20%" align="center"> 181 <a accesskey="u" href="dbc.html">Up</a> 182 </td> 183 <td width="40%" align="right">��<a accesskey="n" href="dbcdel.html">Next</a></td> 184 </tr> 185 <tr> 186 <td width="40%" align="left" valign="top">DBcursor->cmp()��</td> 187 <td width="20%" align="center"> 188 <a accesskey="h" href="index.html">Home</a> 189 </td> 190 <td width="40%" align="right" valign="top">��DBcursor->del()</td> 191 </tr> 192 </table> 193 </div> 194 </body> 195</html> 196