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>DbSequence</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="seq.html" title="Chapter 12. The DbSequence Handle" /> 11 <link rel="prev" href="seq.html" title="Chapter 12. The DbSequence Handle" /> 12 <link rel="next" href="seqclose.html" title="DbSequence::close()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DbSequence</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="seq.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 12. 23 The DbSequence Handle 24 </th> 25 <td width="20%" align="right"> <a accesskey="n" href="seqclose.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="seqcreate"></a>DbSequence</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db_cxx.h> 39 40class DbSequence { 41public: 42 DbSequence(Db *db, u_int32_t flags); 43 ~DbSequence(); 44 45 DB_SEQUENCE *DbSequence::get_DB(); 46 const DB *DbSequence::get_const_DB() const; 47 static DbSequence *DbSequence::get_DbSequence(DB *db); 48 static const DbSequence *DbSequence::get_const_DbSequence(const DB *db); 49 ... 50}; </pre> 51 <p> 52 The <code class="classname">DbSequence</code> handle is the handle used to manipulate a sequence 53 object. A sequence object is stored in a record in a database. 54 </p> 55 <p> 56 57 <code class="classname">DbSequence</code> handles are free-threaded if the 58 <a class="link" href="seqopen.html#seqopen_DB_THREAD">DB_THREAD</a> 59 flag is specified to the 60 <a class="xref" href="seqopen.html" title="DbSequence::open()">DbSequence::open()</a> 61 method when the sequence is opened. Once the 62 <a class="xref" href="seqclose.html" title="DbSequence::close()">DbSequence::close()</a> or 63 <a class="xref" href="seqremove.html" title="DbSequence::remove()">DbSequence::remove()</a> 64 methods are called, the handle can not be accessed again, regardless 65 of the method's return. 66 </p> 67 <p> 68 Each handle opened on a sequence may maintain a separate cache of values which are 69 returned to the application using the <a class="xref" href="seqget.html" title="DbSequence::get()">DbSequence::get()</a> 70 method either singly or in groups 71 depending on its <span class="bold"><strong>delta</strong></span> parameter. 72 </p> 73 <p> 74 Calling the <a class="xref" href="seqclose.html" title="DbSequence::close()">DbSequence::close()</a> 75 or <a class="xref" href="seqremove.html" title="DbSequence::remove()">DbSequence::remove()</a> 76 methods discards this handle. 77 </p> 78 <div class="sect2" lang="en" xml:lang="en"> 79 <div class="titlepage"> 80 <div> 81 <div> 82 <h3 class="title"><a id="id1708960"></a>Parameters</h3> 83 </div> 84 </div> 85 </div> 86 <div class="sect3" lang="en" xml:lang="en"> 87 <div class="titlepage"> 88 <div> 89 <div> 90 <h4 class="title"><a id="id1709021"></a>db</h4> 91 </div> 92 </div> 93 </div> 94 <p> 95 The <span class="bold"><strong>db</strong></span> parameter is an open database 96 handle which holds the persistent data for the sequence. The database 97 may be of any type, but must not have been configured to support 98 duplicate data items. 99 </p> 100 </div> 101 <div class="sect3" lang="en" xml:lang="en"> 102 <div class="titlepage"> 103 <div> 104 <div> 105 <h4 class="title"><a id="id1709131"></a>flags</h4> 106 </div> 107 </div> 108 </div> 109 <p> 110 The <span class="bold"><strong>flags</strong></span> parameter is 111 currently unused, and must be set to 0. 112 </p> 113 </div> 114 </div> 115 <div class="sect2" lang="en" xml:lang="en"> 116 <div class="titlepage"> 117 <div> 118 <div> 119 <h3 class="title"><a id="id1709317"></a>Errors</h3> 120 </div> 121 </div> 122 </div> 123 <p> 124 The <code class="methodname">db_sequence_create</code> <span> 125 126 <span> 127 method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 128 exception, encapsulating one of the following non-zero errors, or return one 129 of the following non-zero errors: 130 </span> 131 </span> 132 </p> 133 <div class="sect3" lang="en" xml:lang="en"> 134 <div class="titlepage"> 135 <div> 136 <div> 137 <h4 class="title"><a id="id1708772"></a>EINVAL</h4> 138 </div> 139 </div> 140 </div> 141 <p> 142 An invalid flag value or parameter was specified. 143 </p> 144 </div> 145 </div> 146 <div class="sect2" lang="en" xml:lang="en"> 147 <div class="titlepage"> 148 <div> 149 <div> 150 <h3 class="title"><a id="id1709262"></a>Class</h3> 151 </div> 152 </div> 153 </div> 154 <p> 155 <a class="link" href="seq.html" title="Chapter 12. The DbSequence Handle">DbSequence</a> 156 </p> 157 </div> 158 <div class="sect2" lang="en" xml:lang="en"> 159 <div class="titlepage"> 160 <div> 161 <div> 162 <h3 class="title"><a id="id1709164"></a>See Also</h3> 163 </div> 164 </div> 165 </div> 166 <p> 167 <a class="xref" href="seq.html#seqlist" title="Sequences and Related Methods">Sequences and Related Methods</a> 168 </p> 169 </div> 170 </div> 171 <div class="navfooter"> 172 <hr /> 173 <table width="100%" summary="Navigation footer"> 174 <tr> 175 <td width="40%" align="left"><a accesskey="p" href="seq.html">Prev</a> </td> 176 <td width="20%" align="center"> 177 <a accesskey="u" href="seq.html">Up</a> 178 </td> 179 <td width="40%" align="right"> <a accesskey="n" href="seqclose.html">Next</a></td> 180 </tr> 181 <tr> 182 <td width="40%" align="left" valign="top">Chapter 12. 183 The DbSequence Handle 184 </td> 185 <td width="20%" align="center"> 186 <a accesskey="h" href="index.html">Home</a> 187 </td> 188 <td width="40%" align="right" valign="top"> DbSequence::close()</td> 189 </tr> 190 </table> 191 </div> 192 </body> 193</html> 194