62 lines
4.0 KiB
HTML
62 lines
4.0 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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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="SQL assignments and comparisons" />
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<meta name="abstract" content="The basic operations of SQL are assignment and comparison." />
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<meta name="description" content="The basic operations of SQL are assignment and comparison." />
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<meta name="DC.Relation" scheme="URI" content="rbagssqlanddbchars.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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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>SQL assignments and comparisons</title>
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</head>
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<body id="rbagssqlasgncompdbcs"><a name="rbagssqlasgncompdbcs"><!-- --></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">SQL assignments and comparisons</h1>
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<div><p>The basic operations of SQL are assignment and comparison.</p>
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<p>Assignment operations are performed during the running of CALL, INSERT,
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UPDATE, FETCH, and SELECT INTO statements. Comparison operations are performed
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during the running of statements that include predicates and other language
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elements such as MAX, MIN, DISTINCT, GROUP BY, and ORDER BY.</p>
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<p>The basic rule for both operations is that the data type of the operands
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involved must be compatible. The compatibility rule also applies to UNION,
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concatenation, and the VALUE, COALESCE, MIN, and MAX scalar functions.</p>
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<div class="section" id="rbagssqlasgncompdbcs__HDRCHARAS"><a name="rbagssqlasgncompdbcs__HDRCHARAS"><!-- --></a><h4 class="sectiontitle">SQL string assignments and double-byte characters</h4><p>The
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basic rule for string assignments is that the length of a string assigned
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to a column must not be greater than the length attribute of the column. (Trailing
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blanks are normally included in the length of the string. For string assignment,
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however, trailing blanks are not included in the length of the string.)</p>
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<p>If
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the string contains mixed data, the assignment rules may require truncation
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within a sequence of double-byte codes. To prevent the loss of the shift-in
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character that ends the double-byte sequence, additional characters might
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be truncated from the end of the string, and a shift-in character added. In
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the truncated result, there is always an even number of bytes between each
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shift-out character and its matching shift-in character.</p>
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<p>Character,
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DBCS-only, DBCS-open, and DBCS-either are not compatible with graphic types
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for assignment.</p>
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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="rbagssqlanddbchars.htm" title="The basic symbols of keywords and operators in the SQL language are single-byte characters that are part of all character sets supported by the IBM relational database products. Characters of the language are classified as letters, digits, or special characters.">SQL and DBCS</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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