110 lines
3.5 KiB
HTML
110 lines
3.5 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>Deleting Records Using Cursors</title>
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<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.62.4" />
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<link rel="home" href="index.html" title="Getting Started with Berkeley DB" />
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<link rel="up" href="Cursors.html" title="Chapter 4. Using Cursors" />
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<link rel="previous" href="PutEntryWCursor.html" title="Putting Records Using Cursors" />
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<link rel="next" href="ReplacingEntryWCursor.html" title="Replacing Records Using Cursors" />
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</head>
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<body>
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<div class="navheader">
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">Deleting Records Using Cursors</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="PutEntryWCursor.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 4. Using Cursors</th>
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<td width="20%" align="right"> <a accesskey="n" href="ReplacingEntryWCursor.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="DeleteEntryWCursor"></a>Deleting Records Using Cursors</h2>
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</div>
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</div>
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<div></div>
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</div>
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<p>
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To delete a record using a cursor, simply position the cursor to the
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record that you want to delete and then call
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<span>
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<span><tt class="methodname">DBC->del()</tt>.</span>
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</span>
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</p>
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<p>For example:</p>
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<a id="c_cursor8"></a>
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<pre class="programlisting">#include <db.h>
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#include <string.h>
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...
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DB *dbp;
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DBC *cursorp;
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DBT key, data;
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char *key1str = "My first string";
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int ret;
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/* Database open omitted */
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/* Initialize our DBTs. */
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memset(&key, 0, sizeof(DBT));
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memset(&data, 0, sizeof(DBT));
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/* Set up our DBTs */
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key.data = key1str;
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key.size = strlen(key1str) + 1;
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/* Get the cursor */
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dbp->cursor(dbp, NULL, &cursorp, 0);
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/* Iterate over the database, deleting each record in turn. */
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while ((ret = cursorp->get(cursorp, &key,
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&data, DB_SET)) == 0) {
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cursorp->del(cursorp, 0);
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}
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/* Cursors must be closed */
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if (cursorp != NULL)
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cursorp->close(cursorp);
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if (dbp != NULL)
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dbp->close(dbp, 0);</pre>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="PutEntryWCursor.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="Cursors.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="ReplacingEntryWCursor.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">Putting Records Using Cursors </td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> Replacing Records Using Cursors</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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