ibm-information-center/dist/eclipse/plugins/i5OS.ic.rzakb_5.4.0.1/rzakbmsttdjfld.htm

128 lines
8.3 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="JFLD (Joined Fields) keyword—join logical files only" />
<meta name="abstract" content="Use this join-level keyword to identify the from and to fields whose values are used to join physical files in a join logical file. These fields are both referred to as join fields." />
<meta name="description" content="Use this join-level keyword to identify the from and to fields whose values are used to join physical files in a join logical file. These fields are both referred to as join fields." />
<meta name="DC.subject" content="JFLD (Joined Fields) keyword, Joined Fields (JFLD) keyword" />
<meta name="keywords" content="JFLD (Joined Fields) keyword, Joined Fields (JFLD) keyword" />
<meta name="DC.Relation" scheme="URI" content="rzakbmstlfkeyw.htm" />
<meta name="DC.Relation" scheme="URI" content="lleng.htm" />
<meta name="DC.Relation" scheme="URI" content="ldata.htm" />
<meta name="DC.Relation" scheme="URI" content="ldec.htm" />
<meta name="DC.Relation" scheme="URI" content="lfusg.htm" />
<meta name="copyright" content="(C) Copyright IBM Corporation 2001, 2006" />
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2001, 2006" />
<meta name="DC.Format" content="XHTML" />
<meta name="DC.Identifier" content="tdjfld" />
<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>Physical and Logical Files, JFLD</title>
</head>
<body id="tdjfld"><a name="tdjfld"><!-- --></a>
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
<h1 class="topictitle1">JFLD (Joined Fields) keyword—join logical files only </h1>
<div><p>Use this join-level keyword to identify the <em>from</em> and <em>to</em> fields
whose values are used to join physical files in a join logical file. These
fields are both referred to as join fields.</p>
<div class="section"><div class="p">The format of the keyword is: <pre>JFLD(from-field-name to-field-name)</pre>
</div>
<p>The
join fields must correspond to fields in the physical files identified on
the JOIN keyword for this join specification. The name you specify on the
JFLD keyword must be the same as the name specified in the physical file unless
it was renamed in the join logical file. If you do not specify a JOIN keyword,
then the JFILE keyword is used.</p>
<p>This keyword is valid only for join
logical files.</p>
<p>At least one JFLD keyword is required for each join specification.
A join specification is identified by J in position 17. Because at least one
join specification is required in a join logical file, you must have at least
one JFLD keyword specified in a join logical file.</p>
<p>These fields need
not also be specified as fields in the record format for a join logical file.</p>
<p>To
specify additional join fields to use when joining physical files, specify
more than one JFLD keyword.</p>
<p>The field names you specify on the JFLD
keyword must be specified either at the field level in the join
record format or in one of the physical files, which are specified on the
JFILE keyword.</p>
<div class="p">The <span class="keyword">i5/OS™</span> operating
system uses the following search order to match join field names with defined
fields:<ol><li>Fields specified in the join logical file at the field level in positions
19 through 28. <div class="note"><span class="notetitle">Note:</span> Fields that specify the CONCAT, RENAME, or SST keyword
are valid as join fields; fields that are specified on CONCAT, RENAME, or
SST keyword cannot be join fields.</div>
</li>
<li>Fields in the physical file specified on the JOIN keyword.</li>
</ol>
</div>
<div class="p">The rules for specifying join fields are as follows: <ul><li>The <em>from</em> field must be found in the <em>from</em> file specified
on the JOIN keyword.</li>
<li>The <em>to</em> field must be found in the <em>to</em> file specified on the
JOIN keyword.</li>
<li>Join fields are not required to be defined in the join record format.</li>
<li><em>From</em> and <em>to</em> fields must have the same field attributes (length,
data type, and decimal positions) but need not have the same name. When the
joined fields in the physical files have different definitions, you must redefine
one or both fields. If you redefine fields, there is a possibility of data
conversion errors.<div class="note"><span class="notetitle">Note:</span> Character fields need not have the same length. The
shorter join field is padded with blanks to equal the length of the longer
join field.</div>
</li>
<li>In a single join specification, the total length of fields specified as <em>to</em> fields
on the JFLD keyword and fields specified on the JDUPSEQ keyword can be up
to 120 bytes.</li>
<li>Binary character fields can be joined only with other binary character
fields.</li>
</ul>
</div>
</div>
<div class="section"><h4 class="sectiontitle">Examples</h4><p>The following examples show how to specify
the JFLD keyword.</p>
</div>
<div class="example"><h4 class="sectiontitle">Example 1</h4><pre>|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A R JREC JFILE(PF1 PF2)
00020A J JOIN(PF1 PF2)
00030A JFLD(NAME1 NAME2)
A</pre>
<p>In the join logical file, the JFLD keywords specify that
NAME1 in physical file PF1 is used to join to NAME2 in physical file PF2.</p>
</div>
<div class="example"><h4 class="sectiontitle">Example 2</h4><pre>|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A R JREC JFILE(PF1 PF2)
00020A J JOIN(PF1 PF2)
00030A JFLD(NAME1 NAME2)
00040A JFLD(ADDR1 ADDR2)
A</pre>
<p>In the join logical file, the JFLD keywords specify that
NAME1 and ADDR1 in physical file PF1 are used to join to NAME2 and ADDR2 in
physical file PF2.</p>
</div>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakbmstlfkeyw.htm" title="This topic lists valid keyword entries for describing physical and logical files. They are typed in positions 45 through 80 (functions).">Keyword entries for physical and logical files (positions 45 through 80)</a></div>
</div>
<div class="relref"><strong>Related reference</strong><br />
<div><a href="lleng.htm" title="Use these positions to specify the length of a physical or logical file field.">Length for physical and logical files (positions 30 through 34)</a></div>
<div><a href="ldata.htm" title="For a physical file, use this position to specify the data type of the field within the database. Specify data type in a logical file only to override or change the data type of the corresponding field in the physical file on which this logical file is based.">Data type for physical and logical files (position 35)</a></div>
<div><a href="ldec.htm" title="Use these positions to specify the decimal placement within a packed decimal, zoned decimal, binary, or floating-point field.">Decimal positions for physical and logical files (positions 36 and 37)</a></div>
<div><a href="lfusg.htm" title="Use this field to specify that a named field is to be an input-only, both (both input and output are allowed), or neither field.">Usage for physical and logical files (position 38)</a></div>
</div>
</div>
</body>
</html>