104 lines
7.0 KiB
HTML
104 lines
7.0 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<meta name="DC.Type" content="reference" />
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<meta name="DC.Title" content="AS400JDBCClob class" />
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<meta name="abstract" content="You can use a AS400JDBCClob object to access character large objects (CLOBs), such as large documents." />
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<meta name="description" content="You can use a AS400JDBCClob object to access character large objects (CLOBs), such as large documents." />
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<meta name="copyright" content="(C) Copyright IBM Corporation 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2006" />
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<meta name="DC.Format" content="XHTML" />
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<meta name="DC.Identifier" content="jdbclob" />
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<meta name="DC.Language" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>AS400JDBCClob class</title>
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</head>
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<body id="jdbclob"><a name="jdbclob"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">AS400JDBCClob class</h1>
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<div><p>You can use a AS400JDBCClob object to access character
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large objects (CLOBs), such as large documents.</p>
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<div class="section"><p> <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html">AS400JDBCClob</a> </p>
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<p>The key difference between the AS400JDBCClob
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class and the AS400JDBCClobLocator class is where the blob is stored. With
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the AS400JDBCClob class, the clob is stored in the database, which inflates
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the size of the database file. The AS400JDBCClobLocator class stores a locator
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(think of it as a pointer) in the database file that points to where the
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clob is located.</p>
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<p>With the AS400JDBCClob class, the lob threshold property
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can be used. This property specifies the maximum large object (LOB) size (in
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kilobytes) that can be retrieved as part of a result set. LOBs that are larger
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than this threshold are retrieved in pieces using extra communication to the
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server. Larger LOB thresholds reduce the frequency of communication to the
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server, but they download more LOB data, even if it is not used. Smaller lob
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thresholds may increase frequency of communication to the server, but they
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only download LOB data as it is needed. See <a href="jdbcproperties.htm#jdbcproperties">IBM Toolbox for Java JDBC properties</a> for
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information on additional properties that are available.</p>
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<p>Using the AS400JDBCClob
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class, you can do the following:</p>
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<ul><li>Return the entire clob as a <a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#GETSUBSTRING(LONG, INT)">stream of ASCII characters</a></li>
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<li>Return the <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#GETCHARACTERSTREAM()">contents</a> of the clob as a character stream</li>
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<li>Return a <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#GETSUBSTRING(LONG, INT)">part of the contents</a> of the clob</li>
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<li>Return the <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#LENGTH()">length</a> of the clob</li>
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<li>Create a <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#SETCHARACTERSTREAM(LONG)">Unicode character stream</a> or an <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#SETASCIISTREAM(LONG)">ASCII character stream</a> to write to the clob</li>
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<li><a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#SETSTRING(LONG, JAVA.LANG.STRING)">Write a String</a> to the clob</li>
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<li><a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#TRUNCATE(LONG)">Truncate</a> the clob</li>
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</ul>
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</div>
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<div class="section" id="jdbclob__clobexamples"><a name="jdbclob__clobexamples"><!-- --></a><h4 class="sectiontitle">Examples</h4><p>The following examples
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show how to use the AS400JDBCClob class to read from a clob and update a clob:</p>
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<p><strong>Example:
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Using the AS400JDBCClob class to read from a clob</strong></p>
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<pre> Clob clob = rs.getClob(1);
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int length = clob.length();
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String s = clob.getSubString(1, (int) length);</pre>
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<p><strong>Example:
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Using the AS400JDBCClob class to update a clob</strong></p>
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<pre> ResultSet rs = statement.executeQuery ("SELECT CLOB FROM MYTABLE");
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rs.absolute(4);
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Clob clob = rs.getClob(1);
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// Change the characters in the clob, starting at the third character
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// of the clob
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clob.setString (3, "Small");
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// Update the clob in the result set, starting at the third character
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// of the clob and truncating the clob at the end of the update string
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// (the clob now has 7 characters).
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rs.updateClob(1, clob);
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// Update the database with the updated clob. This will change the
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// clob in the database starting at the third character of the clob,
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// and truncating at the end of the update string.
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rs.updateRow();
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rs.close();</pre>
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</div>
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<div class="section" id="jdbclob__jdbcclobloc"><a name="jdbclob__jdbcclobloc"><!-- --></a><h4 class="sectiontitle">AS400JDBCClobLocator class</h4><p>You
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can use a <a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#NAVBAR_TOP"> AS400JDBCClobLocator</a> object to access character large
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objects (CLOBs).</p>
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<p>Using the AS400JDBCClobLocator class, you can do the
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following:</p>
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<ul><li>Return the entire clob as a <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#GETASCIISTREAM()">stream of ASCII characters</a></li>
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<li>Return the <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#GETCHARACTERSTREAM()">entire clob</a> as a character stream</li>
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<li>Return a <a href="javadoc/com/ibm/as400/access/AS400JDBCClob.html#GETSUBSTRING(LONG, INT)">part of the contents</a> of the clob</li>
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<li>Return the <a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#LENGTH()">length</a> of the clob</li>
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<li>Create a <a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#SETCHARACTERSTREAM(LONG)">Unicode character stream</a> or an <a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#SETASCIISTREAM(LONG)">ASCII character stream</a> to write to the clob</li>
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<li><a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#SETSTRING(LONG, JAVA.LANG.STRING)">Write a String</a> to the clob</li>
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<li><a href="javadoc/com/ibm/as400/access/AS400JDBCClobLocator.html#TRUNCATE(LONG)">Truncate</a> the clob</li>
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</ul>
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</div>
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</div>
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</body>
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</html>
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