<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Deleting Secondary Database Records</title> <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Getting Started with Berkeley DB" /> <link rel="up" href="indexes.html" title="Chapter 10. Secondary Databases" /> <link rel="prev" href="readSecondary.html" title="Reading Secondary Databases" /> <link rel="next" href="secondaryCursor.html" title="Using Secondary Cursors" /> </head> <body> <div xmlns="" class="navheader"> <div class="libver"> <p>Library Version 12.1.6.1</p> </div> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">Deleting Secondary Database Records</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="readSecondary.html">Prev</a> </td> <th width="60%" align="center">Chapter 10. Secondary Databases</th> <td width="20%" align="right"> <a accesskey="n" href="secondaryCursor.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="secondaryDelete"></a>Deleting Secondary Database Records</h2> </div> </div> </div> <p> In general, you <span>will</span> not modify a secondary database directly. In order to modify a secondary database, you should modify the primary database and simply allow DB to manage the secondary modifications for you. </p> <p> However, as a convenience, you can delete <code class="classname">SecondaryDatabase</code> records directly. Doing so causes the associated primary key/data pair to be deleted. This in turn causes DB to delete all <code class="classname">SecondaryDatabase</code> records that reference the primary record. </p> <p> You can use the <code class="methodname">SecondaryDatabase.delete()</code> method to delete a secondary database record. Note that if your <code class="classname">SecondaryDatabase</code> contains duplicate records, then deleting a record from the set of duplicates causes all of the duplicates to be deleted as well. </p> <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> <h3 class="title">Note</h3> <p> <span><code class="methodname">SecondaryDatabase.delete()</code> causes the previously described delete operations to occur </span> only if the primary database is opened for write access. </p> </div> <p>For example:</p> <a id="java_index7"></a> <pre class="programlisting">package db.GettingStarted; import com.sleepycat.db.DatabaseEntry; import com.sleepycat.db.DatabaseException; import com.sleepycat.db.OperationStatus; import com.sleepycat.db.SecondaryDatabase; ... try { SecondaryDatabase mySecondaryDatabase = null; // Omitting all database opens ... String searchName = "John Doe"; DatabaseEntry searchKey = new DatabaseEntry(searchName.getBytes("UTF-8")); // Delete the first secondary record that uses "John Doe" as // a key. This causes the primary record referenced by this secondary // record to be deleted. OperationStatus retVal = mySecondaryDatabase.delete(null, searchKey); } catch (Exception e) { // Exception handling goes here }</pre> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="readSecondary.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="indexes.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="secondaryCursor.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Reading Secondary Databases </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> <span>Using Secondary Cursors</span> </td> </tr> </table> </div> </body> </html>