65 lines
3.8 KiB
HTML
65 lines
3.8 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 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="Details: Add referential constraints" />
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<meta name="abstract" content="Here is a list of limitations that apply to referential constraints." />
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<meta name="description" content="Here is a list of limitations that apply to referential constraints." />
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<meta name="DC.Relation" scheme="URI" content="rbaforzahfrce.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="rbaforzahfrcf" />
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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>Details: Add referential constraints</title>
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</head>
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<body id="rbaforzahfrcf"><a name="rbaforzahfrcf"><!-- --></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">Details: Add referential constraints</h1>
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<div><p>Here is a list of limitations that apply to referential constraints.</p>
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<div class="p"><ul><li>A parent file must be a physical file.</li>
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<li>A parent file can have a maximum of one member, MAXMBR(1).</li>
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<li>A dependent file must be a physical file.</li>
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<li>A dependent file can have a maximum of one member, MAXMBR(1).</li>
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<li>You can define a constraint when both or either of the dependent and the
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parent files have zero members. A constraint cannot be established
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unless both files have a member.</li>
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<li>A file can have a maximum of one primary key, but might have many unique
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constraints.</li>
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<li>There is a maximum of 300 constraint relations per file. This maximum
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value is the sum of: <ul><li>The referential constraints whether participating as a parent or a dependent,
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and whether the constraints are defined or established.</li>
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<li>The unique constraints, which includes the primary key constraint.</li>
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<li>The check constraints.</li>
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</ul>
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</li>
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<li>Only externally described files are allowed in referential constraints.
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Source files are not allowed. Program described files are not allowed.</li>
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<li>Files with insert, update, or delete capabilities are not allowed in *RESTRICT
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relationships.</li>
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<li>Constraint names must be unique in a library.</li>
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<li>You cannot add constraints to files in the QTEMP library.</li>
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<li>You cannot add a referential constraint where the parent file is in one
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ASP and the dependent file is in a different ASP.</li>
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</ul>
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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="rbaforzahfrce.htm" title="You can add referential constraints on physical files with no more than one member. A referential constraint is a file-level attribute; therefore, you can create the constraint before the member exists.">Add referential constraints</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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