113 lines
7.1 KiB
HTML
113 lines
7.1 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="concept" />
|
||
|
|
<meta name="DC.Title" content="Concatenated fields" />
|
||
|
|
<meta name="abstract" content="Using the CONCAT keyword, you can combine two or more fields from a physical file record format to make one field in a logical file record format." />
|
||
|
|
<meta name="description" content="Using the CONCAT keyword, you can combine two or more fields from a physical file record format to make one field in a logical file record format." />
|
||
|
|
<meta name="DC.subject" content="concatenated field, field, concatenating" />
|
||
|
|
<meta name="keywords" content="concatenated field, field, concatenating" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rbafodescdrv.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="rbafoconfd" />
|
||
|
|
<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>Concatenated fields</title>
|
||
|
|
</head>
|
||
|
|
<body id="rbafoconfd"><a name="rbafoconfd"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Concatenated fields</h1>
|
||
|
|
<div><p>Using the CONCAT keyword, you can combine two or more fields from
|
||
|
|
a physical file record format to make one field in a logical file record format. </p>
|
||
|
|
<p> For example, a physical file record format contains the fields <em>Month</em>, <em>Day</em>,
|
||
|
|
and <em>Year</em>. For a logical file, you concatenate these fields into one
|
||
|
|
field, <em>Date</em>.</p>
|
||
|
|
<div class="p">The field length for the resulting concatenated field is the sum of the
|
||
|
|
lengths of the included fields (unless the fields in the physical file are
|
||
|
|
binary or packed decimal, in which case they are changed to zoned decimal).
|
||
|
|
The field length of the resulting field is automatically calculated by the
|
||
|
|
system. A concatenated field can have: <ul><li>Column headings</li>
|
||
|
|
<li>Validity checking</li>
|
||
|
|
<li>Text description</li>
|
||
|
|
<li>Edit code or edit word (numeric concatenated fields only)</li>
|
||
|
|
</ul>
|
||
|
|
<div class="note"><span class="notetitle">Note:</span> This editing and validity checking information is not used by the
|
||
|
|
database management system but is retrieved when field descriptions from the
|
||
|
|
database file are referred to in a display or printer file.</div>
|
||
|
|
</div>
|
||
|
|
<div class="p">When fields are concatenated, the data types can change (the resulting
|
||
|
|
data type is automatically determined by the system). The following rules
|
||
|
|
and restrictions apply: <ul><li>The operating system assigns the data type based on
|
||
|
|
the data types of the fields that are being concatenated.</li>
|
||
|
|
<li>The maximum length of a concatenated field varies depending on the data
|
||
|
|
type of the concatenated field and the length of the fields being concatenated.
|
||
|
|
If the concatenated field is zoned decimal (S), its total length cannot exceed
|
||
|
|
31 bytes; if it is character (A), its total length cannot exceed 32 766 bytes.</li>
|
||
|
|
<li>In join logical files, the fields to be concatenated must be from the
|
||
|
|
same physical file. The first field specified on the CONCAT keyword identifies
|
||
|
|
which physical file is to be used. The first field must, therefore, be unique
|
||
|
|
among the physical files on which the logical file is based, or you must also
|
||
|
|
specify the JREF keyword to specify which physical file to use.</li>
|
||
|
|
<li>The use of a concatenated field must be I (input only) if the concatenated
|
||
|
|
field is variable length. Otherwise, the use can be B (both input and output).</li>
|
||
|
|
<li>REFSHIFT cannot be specified on a concatenated field that has been assigned
|
||
|
|
a data type of O or J.</li>
|
||
|
|
<li>If any of the fields contain the null value, the result of concatenation
|
||
|
|
is the null value.</li>
|
||
|
|
</ul>
|
||
|
|
<div class="note"><span class="notetitle">Note:</span> For information about concatenating DBCS fields, see <a href="rbafoappdbcs.htm#rbafoappdbcs">Double-byte character set considerations</a>.</div>
|
||
|
|
When
|
||
|
|
only numeric fields are concatenated, the sign of the last field in the group
|
||
|
|
is used as the sign of the concatenated field. <div class="note"><span class="notetitle">Notes:</span> <ol><li>Numeric fields with decimal precision other than zero cannot be included
|
||
|
|
in a concatenated field.</li>
|
||
|
|
<li>Date, time, timestamp, and floating-point fields cannot be included in
|
||
|
|
a concatenated field.</li>
|
||
|
|
</ol>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<p>The following example shows the field description in data description specifications
|
||
|
|
(DDS) for concatenation. (The CONCAT keyword is used to specify the fields
|
||
|
|
to concatenate.)</p>
|
||
|
|
<pre>|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
|
||
|
|
A
|
||
|
|
00101A MONTH
|
||
|
|
00102A DAY
|
||
|
|
00103A YEAR
|
||
|
|
00104A DATE CONCAT(MONTH DAY YEAR)
|
||
|
|
A</pre>
|
||
|
|
<div class="p">In this example, the logical file record format includes the separate fields
|
||
|
|
of <em>Month</em>, <em>Day</em>, and <em>Year</em>, as well as the concatenated <em>Date</em> field.
|
||
|
|
Any of the following formats can be used: <ul><li>A format with the separate fields of <em>Month</em>, <em>Day</em>, and <em>Year</em></li>
|
||
|
|
<li>A format with only the concatenated <em>Date</em> field</li>
|
||
|
|
<li>A format with the separate fields <em>Month</em>, <em>Day</em>, <em>Year</em> and
|
||
|
|
the concatenated <em>Date</em> field</li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
<p>When both separate and concatenated fields exist in the format, any updates
|
||
|
|
to the fields are processed in the sequence in which the DDS is specified.
|
||
|
|
In the previous example, if the <em>Date</em> field contained 103188 and the <em>Month</em> field
|
||
|
|
is changed to 12, when the record is updated, the month in the <em>Date</em> field
|
||
|
|
would be used. The updated record would contain 103188. If the <em>Date</em> field
|
||
|
|
were specified first, the updated record would contain 123188.</p>
|
||
|
|
<p>Concatenated fields can also be used as key fields and select/omit fields.</p>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafodescdrv.htm" title="Fields in a logical file can be derived from fields in the physical file on which the logical file is based or from fields in the same logical file.">Derive new fields from existing fields</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|