53 lines
3.2 KiB
HTML
53 lines
3.2 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 name="Robots" content="index,follow" />
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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="Remove constraints" />
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<meta name="abstract" content="This example removes the primary key over column DEPTNO in table DEPARTMENT." />
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<meta name="description" content="This example removes the primary key over column DEPTNO in table DEPARTMENT." />
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<meta name="DC.subject" content="examples, removing constraints, CREATE TABLE statement, constraints, example removing, ALTER TABLE statement, constraint, example, removing" />
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<meta name="keywords" content="examples, removing constraints, CREATE TABLE statement, constraints, example removing, ALTER TABLE statement, constraint, example, removing" />
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<meta name="DC.Relation" scheme="URI" content="rbafysqlpctablecreate.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="rbafyremovecon" />
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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>Remove constraints</title>
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</head>
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<body id="rbafyremovecon"><a name="rbafyremovecon"><!-- --></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">Remove constraints</h1>
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<div><p>This example removes the primary key over column DEPTNO
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in table DEPARTMENT.</p>
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<div class="section"><p>The constraints REPORTS_TO_EXISTS, defined on table DEPARTMENT,
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and WORKDEPT_EXISTS, defined on table EMPLOYEE, will be removed as well, since
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the primary key being removed is the parent key in those constraint relationships.
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</p>
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<pre> <strong>ALTER TABLE</strong> CORPDATA.EMPLOYEE <strong>DROP PRIMARY KEY</strong></pre>
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</div>
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<div class="section"><p>You can also remove a constraint by name, as in the following
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example: </p>
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<pre> <strong>ALTER TABLE</strong> CORPDATA.DEPARTMENT
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<strong>DROP CONSTRAINT</strong> UNIQUE_LNAME_IN_DEPT</pre>
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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="rbafysqlpctablecreate.htm" title="A table can be visualized as a two-dimensional arrangement of data consisting of rows and columns.">Create a table</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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