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>db join</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 TCL API Reference" /> 10 <link rel="up" href="tclapi.html" title="Chapter��1.�� Berkeley DB Tcl APIs" /> 11 <link rel="prev" href="db_is_byteswapped.html" title="db is_byteswapped" /> 12 <link rel="next" href="db_open.html" title="berkdb open" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center"><span class="emphasis"><em>db</em></span> join</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="db_is_byteswapped.html">Prev</a>��</td> 22 <th width="60%" align="center">Chapter��1.�� 23 Berkeley DB Tcl APIs 24 </th> 25 <td width="20%" align="right">��<a accesskey="n" href="db_open.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="db_join"></a><span class="emphasis"><em>db</em></span> join</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">db join 39 <span class="emphasis"><em>db.cX</em></span> 40 <span class="emphasis"><em>db.cY</em></span> 41 <span class="emphasis"><em>db.cZ</em></span> 42 ... </pre> 43 <p> 44 The <span class="emphasis"><em>db</em></span> <span class="bold"><strong>join</strong></span> 45 command joins the specified cursors and returns a cursor handle that 46 can be used to iterate through the joined {key data} pairs. The 47 returned cursor handle is bound to a Tcl command of the form <span class="bold"><strong>dbN.cX</strong></span>, where X is an integer starting at 0 48 (for example, db0.c0 and db0.c1). It is through this Tcl command that 49 the script accesses the cursor methods. 50 </p> 51 <p> 52 The returned join cursor has limited cursor functionality, and only 53 the <span class="emphasis"><em>dbc</em></span> <span class="bold"><strong>get</strong></span> and 54 <span class="emphasis"><em>dbc</em></span> <span class="bold"><strong>close</strong></span> 55 commands will succeed. 56 </p> 57 <p> 58 See <a href="../../programmer_reference/am_cursor.html#am_join" class="olink">Equality Join</a> 59 in the <em class="citetitle">Berkeley DB Programmer's Reference Guide</em> for more 60 information on the underlying requirements for joining. 61 </p> 62 <p> 63 In a transaction-protected environment, all the cursors listed must 64 have been created within the same transaction. 65 </p> 66 <p> 67 In the case of error, a Tcl error is thrown. 68 </p> 69 </div> 70 <div class="navfooter"> 71 <hr /> 72 <table width="100%" summary="Navigation footer"> 73 <tr> 74 <td width="40%" align="left"><a accesskey="p" href="db_is_byteswapped.html">Prev</a>��</td> 75 <td width="20%" align="center"> 76 <a accesskey="u" href="tclapi.html">Up</a> 77 </td> 78 <td width="40%" align="right">��<a accesskey="n" href="db_open.html">Next</a></td> 79 </tr> 80 <tr> 81 <td width="40%" align="left" valign="top"><span class="emphasis"><em>db</em></span> is_byteswapped��</td> 82 <td width="20%" align="center"> 83 <a accesskey="h" href="index.html">Home</a> 84 </td> 85 <td width="40%" align="right" valign="top">��berkdb open</td> 86 </tr> 87 </table> 88 </div> 89 </body> 90</html> 91