80 lines
6.1 KiB
HTML
80 lines
6.1 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 name="security" content="public" />
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<meta name="Robots" content="index,follow" />
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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="concept" />
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<meta name="DC.Title" content="Statement types" />
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<meta name="abstract" content="The Statement interface and its PreparedStatement and CallableStatement subclasses are used to process structured query language (SQL) commands against the database. SQL statements cause the generation of ResultSet objects." />
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<meta name="description" content="The Statement interface and its PreparedStatement and CallableStatement subclasses are used to process structured query language (SQL) commands against the database. SQL statements cause the generation of ResultSet objects." />
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<meta name="DC.Relation" scheme="URI" content="jdbc.htm" />
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<meta name="DC.Relation" scheme="URI" content="statemnt.htm" />
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<meta name="DC.Relation" scheme="URI" content="prepstat.htm" />
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<meta name="DC.Relation" scheme="URI" content="callable.htm" />
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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="statetyp" />
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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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<!-- US Government Users Restricted Rights -->
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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>Statement types</title>
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</head>
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<body id="statetyp"><a name="statetyp"><!-- --></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">Statement types</h1>
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<div><p>The Statement interface and its PreparedStatement and CallableStatement
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subclasses are used to process structured query language (SQL) commands against
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the database. SQL statements cause the generation of ResultSet objects.</p>
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<p>Subclasses of the Statement interface are created with a number of methods
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on the Connection interface. A single Connection object can have many Statement
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objects created under it simultaneously. In past releases, it was possible
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to give exact numbers of Statement objects that could be created. It is impossible
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to do so in this release because different types of Statement objects take
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different numbers of "handles" within the database engine. Therefore, the
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types of Statement objects you are using influence the number of statements
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that can be active under a connection at a single time.</p>
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<p>An application calls the Statement.close method to indicate that the application
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has finished processing a statement. All Statement objects are closed when
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the connection that created them is closed. However, you should not fully
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rely on this behavior to close Statement objects. For example, if your application
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changes so that a connection pool is used instead of explicitly closing the
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connections, the application "leaks" statement handles because the connections
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never close. Closing Statement objects as soon as they are no longer required
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allows external database resources that the statement is using to be released
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immediately.</p>
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<p>The native JDBC driver attempts to detect statement leaks and handles them
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on you behalf. However, relying on that support results in poorer performance.</p>
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<p>Due to the inheritance hierarchy that CallableStatement extends
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PreparedStatement which extends Statement, features of each interface are
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available in the class that extend the interface. For example, features of
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the Statement class are also supported in the PreparedStatement and CallableStatement
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classes. The main exception is the executeQuery, executeUpdate, and execute
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methods on the Statement class. These methods take in an SQL statement to
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dynamically process and cause exceptions if you attempt to use them with PreparedStatement
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or CallableStatement objects.</p>
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</div>
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<div>
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<ul class="ullinks">
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<li class="ulchildlink"><strong><a href="statemnt.htm">Statements</a></strong><br />
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A Statement object is used for processing a static SQL statement and obtaining the results produced by it. Only one ResultSet for each Statement object can be open at a time. All statement methods that process an SQL statement implicitly close a statement's current ResultSet if an open one exists.</li>
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<li class="ulchildlink"><strong><a href="prepstat.htm">PreparedStatements</a></strong><br />
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PreparedStatements extend the Statement interface and provide support for adding parameters to SQL statements.</li>
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<li class="ulchildlink"><strong><a href="callable.htm">CallableStatements</a></strong><br />
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The CallableStatement interface extends PreparedStatement and provides support for output and input/output parameters. The CallableStatement interface also has support for input parameters that is provided by the PreparedStatement interface.</li>
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</ul>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="jdbc.htm" title="The IBM Developer Kit for Java JDBC driver, also known as the "native" driver, provides programmatic access to iSeries database files. Using the Java Database Connectivity (JDBC) API, applications written in the Java language can access JDBC database functions with embedded Structured Query Language (SQL), run SQL statements, retrieve results, and propagate changes back to the database. The JDBC API can also be used to interact with multiple data sources in a distributed, heterogeneous environment.">Access your iSeries database with the IBM Developer Kit for Java JDBC driver</a></div>
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</div>
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</div>
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</body>
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</html>
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