64 lines
3.9 KiB
HTML
64 lines
3.9 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="Example: Counting" />
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<meta name="abstract" content="Your simple counting function returns a 1 the first time and increments the result by one each time it is called. This function takes no SQL arguments, and by definition it is a NOT DETERMINISTIC function since its answer varies from call to call." />
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<meta name="description" content="Your simple counting function returns a 1 the first time and increments the result by one each time it is called. This function takes no SQL arguments, and by definition it is a NOT DETERMINISTIC function since its answer varies from call to call." />
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<meta name="DC.subject" content="examples, counting and defining UDFs, CREATE FUNCTION statement, counting example" />
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<meta name="keywords" content="examples, counting and defining UDFs, CREATE FUNCTION statement, counting example" />
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<meta name="DC.Relation" scheme="URI" content="rbafyudfdudf.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Format" content="XHTML" />
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<meta name="DC.Identifier" content="rbafyudfcfx6" />
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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>Example: Counting </title>
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</head>
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<body id="rbafyudfcfx6"><a name="rbafyudfcfx6"><!-- --></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">Example: Counting </h1>
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<div><p>Your simple counting function returns a <samp class="codeph">1</samp> the
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first time and increments the result by one each time it is called. This function
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takes no SQL arguments, and by definition it is a NOT DETERMINISTIC function
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since its answer varies from call to call.</p>
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<div class="section"><p>It uses the SCRATCHPAD to save the last value returned. Each time
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it is called, the function increments this value and returns it.</p>
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<pre> <strong>CREATE FUNCTION</strong> COUNTER ()
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<strong>RETURNS INT</strong>
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<strong>EXTERNAL NAME</strong> 'MYLIB/MYFUNCS(CTR)'
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<strong> LANGUAGE C
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PARAMETER STYLE DB2SQL
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NO SQL
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NOT DETERMINISTIC
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NOT FENCED
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SCRATCHPAD 4
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DISALLOW PARALLEL</strong></pre>
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</div>
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<div class="section"><p>Note that no parameter definitions are provided, just empty parentheses.
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The above function specifies SCRATCHPAD and uses the default specification
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of NO FINAL CALL. In this case, the size of the scratchpad is set to only
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4 bytes, which is sufficient for a counter. Since the COUNTER function requires
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that a single scratchpad be used to operate properly, DISALLOW PARALLEL is
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added to prevent DB2<sup>®</sup> from operating it in parallel.</p>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafyudfdudf.htm" title="A UDF must be registered in the database before the function can be recognized and used by SQL.">Register UDFs</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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