File: DeleteEntryWCursor.html

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<?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 Records Using Cursors</title>
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    <link rel="start" href="index.html" title="Getting Started with Berkeley DB" />
    <link rel="up" href="Cursors.html" title="Chapter 9. Using Cursors" />
    <link rel="prev" href="PutEntryWCursor.html" title="Putting Records Using Cursors" />
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    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">Deleting Records Using Cursors</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="PutEntryWCursor.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 9. Using Cursors</th>
          <td width="20%" align="right"> <a accesskey="n" href="ReplacingEntryWCursor.html">Next</a></td>
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    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="DeleteEntryWCursor"></a>Deleting Records Using Cursors</h2>
          </div>
        </div>
      </div>
      <p>

        To delete a record using a cursor, simply position the cursor to the
        record that you want to delete and then call 
        
        
        
        
    </p>
      <p>For example:</p>
      <a id="java_cursor8"></a>
      <pre class="programlisting">package db.GettingStarted;
    
import com.sleepycat.db.Cursor;
import com.sleepycat.db.Database;
import com.sleepycat.db.DatabaseEntry;
import com.sleepycat.db.LockMode;
import com.sleepycat.db.OperationStatus; 

...

Cursor cursor = null;
Database myDatabase = null;
try {
    ...
    // Database open omitted for brevity
    ...
    // Create DatabaseEntry objects
    // searchKey is some String.
    DatabaseEntry theKey = new DatabaseEntry(searchKey.getBytes("UTF-8"));
    DatabaseEntry theData = new DatabaseEntry();

    // Open a cursor using a database handle
    cursor = myDatabase.openCursor(null, null);

    // Position the cursor. Ignoring the return value for clarity
    OperationStatus retVal = cursor.getSearchKey(theKey, theData, 
                                                 LockMode.DEFAULT);
    
    // Count the number of records using the given key. If there is only
    // one, delete that record.
    if (cursor.count() == 1) {
            System.out.println("Deleting " + 
                               new String(theKey.getData(), "UTF-8") + 
                               "|" + 
                               new String(theData.getData(), "UTF-8"));
            cursor.delete();
    }
} catch (Exception e) {
    // Exception handling goes here
} finally {
   // Make sure to close the cursor
   cursor.close();
}</pre>
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