64 lines
3.8 KiB
HTML
64 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 name="DC.Type" content="reference" />
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<meta name="DC.Title" content="Indicator variables used to set null values" />
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<meta name="abstract" content="You can use an indicator variable to set a null value in a column." />
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<meta name="description" content="You can use an indicator variable to set a null value in a column." />
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<meta name="DC.subject" content="null value, set by indicator variable, indicator variable, used to set null value, host structure, variable, examples, used to set null value" />
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<meta name="keywords" content="null value, set by indicator variable, indicator variable, used to set null value, host structure, variable, examples, used to set null value" />
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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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<title>Indicator variables used to set null values</title>
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</head>
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<body id="rzajpnullvar"><a name="rzajpnullvar"><!-- --></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">Indicator variables used to set null values</h1>
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<div><p>You can use an indicator variable to set a null value in a column.</p>
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<div class="section"><p>When processing UPDATE or INSERT statements, SQL checks the indicator
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variable (if it exists). If it contains a negative value, the column value
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is set to null. If it contains a value greater than -1, the associated host
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variable contains a value for the column.</p>
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</div>
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<div class="section"><p>For example, you can specify that a value be put in a column (using
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an INSERT or UPDATE statement), but you may not be sure that the value was
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specified with the input data. To provide the capability to set a column to
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a null value, you can write the following statement: </p>
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<pre>EXEC SQL
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<strong>UPDATE</strong> CORPDATA.EMPLOYEE
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<strong>SET</strong> PHONENO = :NEWPHONE:PHONEIND
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<strong>WHERE</strong> EMPNO = :EMPID
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END-EXEC.</pre>
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</div>
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<div class="section"><p>When NEWPHONE contains other than a null value, set PHONEIND to
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zero by preceding the statement with: </p>
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<pre>MOVE 0 to PHONEIND.</pre>
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</div>
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<div class="section"><p>Otherwise, to tell SQL that NEWPHONE contains a null value, set
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PHONEIND to a negative value, as follows: </p>
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<pre>MOVE -1 TO PHONEIND.</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="rzajpindvar.htm" title="An indicator variable is a halfword integer variable used to indicate whether its associated host variable has been assigned a null value.">Indicator variables in applications that use SQL</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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