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Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: luhuayi <luhuayi@huawei.com> Co-committed-by: luhuayi <luhuayi@huawei.com>
34 lines
2.4 KiB
HTML
34 lines
2.4 KiB
HTML
<a name="EN-US_TOPIC_0000001764491772"></a><a name="EN-US_TOPIC_0000001764491772"></a>
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<h1 class="topictitle1">NULL Statements</h1>
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<div id="body8662426"><p id="EN-US_TOPIC_0000001764491772__p725623614578">In PL/SQL programs, a <strong id="EN-US_TOPIC_0000001764491772__b1779310141113">NULL</strong> statement can be used to indicate "do nothing", which is also known as an empty statement.</p>
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<p id="EN-US_TOPIC_0000001764491772__a0261909453bc42bcb3051b27d3270864">A NULL statement acts as a placeholder and can give meaning to certain statements, improving the readability of the program.</p>
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<div class="section" id="EN-US_TOPIC_0000001764491772__s116fc7ddf8074de7839a921a63f1a598"><h4 class="sectiontitle">Syntax</h4><p id="EN-US_TOPIC_0000001764491772__ab59772b352fa433c94f3f790c0ef770b">The following shows example use of NULL statements.</p>
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<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001764491772__s6f3fcc3ee1f54ec5a21784bb38ee9bce"><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">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 class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_04_0532.html">GaussDB(DWS) Stored Procedure Control Statements</a></div>
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</div>
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</div>
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