je/docs/GettingStartedGuide/ReplacingEntryWCursor.html
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<title>Replacing Records Using Cursors</title>
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<link rel="up" href="Cursors.html" title="Chapter 9. Using Cursors" />
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<p>Library Version 12.2.7.5</p>
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<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">Replacing Records Using Cursors</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="DeleteEntryWCursor.html">Prev</a> </td>
<th width="60%" align="center">Chapter 9. Using Cursors</th>
<td width="20%" align="right"> <a accesskey="n" href="cursorUsage.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="ReplacingEntryWCursor"></a>Replacing Records Using Cursors</h2>
</div>
</div>
</div>
<p>
You replace the data for a database record by using
<span>
<code class="methodname">Cursor.putCurrent()</code>.
This method takes just one
argument — the data that you want to write to the current location in the
database.
</span>
</p>
<a id="je_cursor9"></a>
<pre class="programlisting">import com.sleepycat.je.Cursor;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;
...
Cursor cursor = null;
try {
...
// Database and environment 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);
// Replacement data
String replaceStr = "My replacement string";
DatabaseEntry replacementData =
new DatabaseEntry(replaceStr.getBytes("UTF-8"));
cursor.putCurrent(replacementData);
} catch (Exception e) {
// Exception handling goes here
} finally {
// Make sure to close the cursor
cursor.close();
}</pre>
<p>
Note that this method cannot be used if the record that you are trying
to replace is a member of a duplicate set. This is because records must
be sorted by their data and replacement would violate that sort order.
</p>
<p>
<span>If</span>
you want to replace the data contained by a duplicate record,
delete the record and create a new record with the desired key and data.
</p>
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<td width="40%" align="left" valign="top">Deleting Records Using Cursors </td>
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<a accesskey="h" href="index.html">Home</a>
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<td width="40%" align="right" valign="top"> Cursor Example</td>
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