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Lu, Huayi
e6fa411af0
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
34 lines
2.2 KiB
HTML
34 lines
2.2 KiB
HTML
<a name="EN-US_TOPIC_0000001233563321"></a><a name="EN-US_TOPIC_0000001233563321"></a>
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<h1 class="topictitle1">NULL Statements</h1>
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<div id="body8662426"><p id="EN-US_TOPIC_0000001233563321__a3a3fa87a964a4bbdac228c86cd6b94f7">In PL/SQL programs, <strong id="EN-US_TOPIC_0000001233563321__a8781d5938e9c44f08b8dd3dcca8414a4">NULL</strong> statements are used to indicate "nothing should be done", equal to placeholders. They grant meanings to some statements and improve program readability.</p>
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<div class="section" id="EN-US_TOPIC_0000001233563321__scd3bb91d4a9d489ea0b1b259615ebacf"><h4 class="sectiontitle">Syntax</h4><p id="EN-US_TOPIC_0000001233563321__a2d6f7826b3c44855ad231cf8d498fcd8">The following shows example use of NULL statements.</p>
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<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233563321__s36232b494bc44d0cac809dee4f045723"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
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<span class="normal">4</span>
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<span class="normal">9</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">DECLARE</span>
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<span class="w"> </span><span class="p">...</span>
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<span class="k">BEGIN</span>
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<span class="w"> </span><span class="p">...</span>
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<span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="n">v_num</span><span class="w"> </span><span class="k">IS</span><span class="w"> </span><span class="k">NULL</span><span class="w"> </span><span class="k">THEN</span>
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<span class="w"> </span><span class="k">NULL</span><span class="p">;</span><span class="w"> </span><span class="c1">--No data needs to be processed.</span>
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<span class="w"> </span><span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="p">;</span>
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<span class="k">END</span><span class="p">;</span>
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<span class="o">/</span>
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</pre></div></td></tr></table></div>
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</div>
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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="dws_04_0532.html">Control Statements</a></div>
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</div>
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</div>
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