109 lines
6.1 KiB
HTML
109 lines
6.1 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE html
|
||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html lang="en-us" xml:lang="en-us">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="security" content="public" />
|
||
|
|
<meta name="Robots" content="index,follow" />
|
||
|
|
<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))' />
|
||
|
|
<meta name="DC.Type" content="reference" />
|
||
|
|
<meta name="DC.Title" content="Example 1: Define fields derived from existing field definitions" />
|
||
|
|
<meta name="abstract" content="This example shows the use of derived fields." />
|
||
|
|
<meta name="description" content="This example shows the use of derived fields." />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rbafofdefd.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rbafofdefdex1" />
|
||
|
|
<meta name="DC.Language" content="en-us" />
|
||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
||
|
|
<!-- US Government Users Restricted Rights -->
|
||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
||
|
|
<title>Example 1: Define fields derived from existing field definitions</title>
|
||
|
|
</head>
|
||
|
|
<body id="rbafofdefdex1"><a name="rbafofdefdex1"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Example 1: Define fields derived from existing field definitions</h1>
|
||
|
|
<div><p>This example shows the use of derived fields.</p>
|
||
|
|
<div class="section"><p>Assume that you have the <em>Price</em> and <em>Qty</em> fields in
|
||
|
|
the record format. You can multiply one field by the other by using the Open
|
||
|
|
Query File (OPNQRYF) command to create the derived <em>Exten</em> field. You
|
||
|
|
want FILEA to be processed, and you have already created FILEAA. Assume that
|
||
|
|
the record formats for the files contain the following fields:</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<table cellpadding="4" cellspacing="0" border="1" class="tableborder"><tr><td>
|
||
|
|
<table cellpadding="4" cellspacing="0" summary="" width="100%" border="0"><thead align="left"><tr><th align="left" valign="bottom" width="50%" id="d0e30">FILEA</th>
|
||
|
|
<th align="left" valign="bottom" width="50%" id="d0e32">FILEAA</th>
|
||
|
|
</tr>
|
||
|
|
</thead>
|
||
|
|
<tbody><tr><td align="left" valign="top" width="50%" headers="d0e30 ">Order</td>
|
||
|
|
<td align="left" valign="top" width="50%" headers="d0e32 ">Order</td>
|
||
|
|
</tr>
|
||
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e30 ">Item</td>
|
||
|
|
<td align="left" valign="top" width="50%" headers="d0e32 ">Item</td>
|
||
|
|
</tr>
|
||
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e30 ">Qty</td>
|
||
|
|
<td align="left" valign="top" width="50%" headers="d0e32 ">Exten</td>
|
||
|
|
</tr>
|
||
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e30 ">Price</td>
|
||
|
|
<td align="left" valign="top" width="50%" headers="d0e32 ">Brfdsc</td>
|
||
|
|
</tr>
|
||
|
|
<tr><td align="left" valign="top" width="50%" headers="d0e30 ">Descrp</td>
|
||
|
|
<td valign="top" width="50%" headers="d0e32 "> </td>
|
||
|
|
</tr>
|
||
|
|
</tbody>
|
||
|
|
</table>
|
||
|
|
</td></tr></table>
|
||
|
|
<div class="section"><p>The <em>Exten</em> field is a mapped field. Its value is determined
|
||
|
|
by multiplying <em>Qty</em> times <em>Price</em>. It is not necessary to have
|
||
|
|
either the <em>Qty</em> or <em>Price</em> field in the new format, but they can
|
||
|
|
exist in that format, too, if you want. The <em>Brfdsc</em> field is a brief
|
||
|
|
description of the <em>Descrp</em> field (it uses the first 10 characters).</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><div class="p">Assume that you have specified PGMF to process the
|
||
|
|
new format. To create this program, use FILEAA as the file to read. You can
|
||
|
|
specify: <pre>OVRDBF FILE(FILEAA) TOFILE(FILEA) SHARE(*YES)
|
||
|
|
OPNQRYF FILE(FILEA) FORMAT(FILEAA) +
|
||
|
|
MAPFLD((EXTEN 'PRICE * QTY') +
|
||
|
|
(BRFDSC 'DESCRP'))
|
||
|
|
CALL PGM(PGMF) /* Created using file FILEAA as input */
|
||
|
|
CLOF OPNID(FILEA)
|
||
|
|
DLTOVR FILE(FILEAA)</pre>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>Notice that the attributes of the <em>Exten</em> field are those
|
||
|
|
defined in the record format for FILEAA. If the value calculated for the field
|
||
|
|
is too large, an exception is sent to the program.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>It is not necessary to use the substring function to map to the <em>Brfdsc</em> field
|
||
|
|
if you only want the characters from the beginning of the field. The length
|
||
|
|
of the <em>Brfdsc</em> field is defined in the FILEAA record format.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section"><div class="p">All fields in the format specified on the FORMAT parameter must
|
||
|
|
be described on the OPNQRYF command. That is, all fields in the output format
|
||
|
|
must either exist in one of the record formats for the files specified on
|
||
|
|
the FILE parameter or be defined on the MAPFLD parameter. If you have fields
|
||
|
|
in the format on the FORMAT parameter that your program does not use, you
|
||
|
|
can use the MAPFLD parameter to place zeros or blanks in the fields. Assume
|
||
|
|
the <em>Fldc</em> field is a character field and the <em>Fldn</em> field is a
|
||
|
|
numeric field in the output format, and you are using neither value in your
|
||
|
|
program. You can avoid an error on the OPNQRYF command by specifying: <pre>MAPFLD((FLDC ' " " ')(FLDN 0))</pre>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div class="section"><p>Notice quotation marks enclose a blank value. By using a constant
|
||
|
|
for the definition of an unused field, you avoid having to create a unique
|
||
|
|
format for each use of the OPNQRYF command.</p>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafofdefd.htm" title="Listed here are the operations allowed by defining fields derived from existing field definitions.">Define fields derived from existing field definitions</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|