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Lu, Huayi 27019c2991 DWS TOOL 830.201 version 
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
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>
2024-05-16 07:35:25 +00:00

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<a name="EN-US_TOPIC_0000001819416169"></a><a name="EN-US_TOPIC_0000001819416169"></a>
<h1 class="topictitle1">Order of Clauses</h1>
<div id="body8662426"><p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p5252132416269">For Teradata migration of <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b17436575463226">SELECT </strong>statements, all the clauses (<strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b5332196413226">FROM</strong>, <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b16098063893226">WHERE</strong>, <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b12481996563226">HAVING</strong> and <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b15737437803226">GROUP BY</strong>) can be listed in any order. The tool will not migrate the statement if it contains <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b16972261963226">a QUALIFY </strong>as an <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b17103479313226">ALIAS </strong>before the <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b8619228493226">FROM </strong>clause.</p>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p16182231103319">Use the <strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b4958114403226"><a href="dws_16_0014.html#EN-US_TOPIC_0000001819416085__en-us_topic_0000001706224349_en-us_topic_0000001432527901_li1163915119179">tdMigrateALIAS</a></strong> configuration parameter to configure migration of ALIAS.</p>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p112522245266"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b1335720373226">Input: Order of Clauses</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen1751011516710"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="n">expr1</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">alias1</span>
<span class="w"> </span><span class="p">,</span><span class="w"> </span><span class="n">expr2</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">alias2</span><span class="w"> </span>
<span class="w"> </span><span class="p">,</span><span class="w"> </span><span class="n">expr3</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">alias3</span>
<span class="w"> </span><span class="p">,</span><span class="w"> </span><span class="k">MAX</span><span class="p">(</span><span class="w"> </span><span class="n">expr4</span><span class="w"> </span><span class="p">),</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">tab1</span><span class="w"> </span><span class="n">T1</span><span class="w"> </span><span class="k">INNER</span><span class="w"> </span><span class="k">JOIN</span><span class="w"> </span><span class="n">tab2</span><span class="w"> </span><span class="n">T2</span>
<span class="w"> </span><span class="k">ON</span><span class="w"> </span><span class="n">T1</span><span class="p">.</span><span class="n">c1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">T2</span><span class="p">.</span><span class="n">c2</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">T3</span><span class="p">.</span><span class="n">c5</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'010'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">T1</span><span class="p">.</span><span class="n">c7</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'000'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">HAVING</span><span class="w"> </span><span class="n">alias1</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'IC'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">alias2</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'IC'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">alias3</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">''</span>
<span class="w"> </span><span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="w"> </span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p17513135117712"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b2215120165517">Output</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen195561659164718"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span>
<span class="normal">15</span>
<span class="normal">16</span>
<span class="normal">17</span>
<span class="normal">18</span>
<span class="normal">19</span>
<span class="normal">20</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span>
<span class="w"> </span><span class="n">expr1</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="ss">&quot;alias1&quot;</span>
<span class="w"> </span><span class="p">,</span><span class="n">expr2</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="ss">&quot;alias2&quot;</span>
<span class="w"> </span><span class="p">,</span><span class="n">expr3</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="ss">&quot;alias3&quot;</span>
<span class="w"> </span><span class="p">,</span><span class="k">MAX</span><span class="p">(</span><span class="w"> </span><span class="n">expr4</span><span class="w"> </span><span class="p">)</span>
<span class="w"> </span><span class="p">,...</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="n">tab1</span><span class="w"> </span><span class="n">T1</span><span class="w"> </span><span class="k">INNER</span><span class="w"> </span><span class="k">JOIN</span><span class="w"> </span><span class="n">tab2</span><span class="w"> </span><span class="n">T2</span>
<span class="w"> </span><span class="k">ON</span><span class="w"> </span><span class="n">T1</span><span class="p">.</span><span class="n">c1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">T2</span><span class="p">.</span><span class="n">c2</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">T3</span><span class="p">.</span><span class="n">c5</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'010'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">T1</span><span class="p">.</span><span class="n">c7</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'000'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="p">...</span>
<span class="w"> </span><span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span>
<span class="w"> </span><span class="mi">1</span><span class="w"> </span><span class="p">,</span><span class="mi">2</span><span class="w"> </span><span class="p">,</span><span class="mi">3</span>
<span class="w"> </span><span class="k">HAVING</span>
<span class="w"> </span><span class="n">alias1</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'IC'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">alias2</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">'IC'</span>
<span class="w"> </span><span class="k">AND</span><span class="w"> </span><span class="n">alias3</span><span class="w"> </span><span class="o">&lt;&gt;</span><span class="w"> </span><span class="s1">''</span><span class="w"> </span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p0289112118321"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b1273301310550">Input: Order of Clauses</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen1729082173212"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span>
<span class="normal">3</span>
<span class="normal">4</span>
<span class="normal">5</span>
<span class="normal">6</span>
<span class="normal">7</span>
<span class="normal">8</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span>
<span class="w"> </span><span class="n">TOP</span><span class="w"> </span><span class="mi">10</span><span class="w"> </span><span class="o">*</span>
<span class="w"> </span><span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span>
<span class="w"> </span><span class="n">DeptNo</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">empID</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">100</span>
<span class="k">FROM</span>
<span class="w"> </span><span class="n">tbl_employee</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p82951421203217"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b2164141014552">Output</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen1529610213324"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span>
<span class="normal">3</span>
<span class="normal">4</span>
<span class="normal">5</span>
<span class="normal">6</span>
<span class="normal">7</span>
<span class="normal">8</span>
<span class="normal">9</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span>
<span class="w"> </span><span class="o">*</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="n">tbl_employee</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">empID</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="mi">100</span>
<span class="w"> </span><span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span>
<span class="w"> </span><span class="n">DeptNo</span><span class="w"> </span><span class="k">LIMIT</span><span class="w"> </span><span class="mi">10</span>
<span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<div class="note" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_note1813394893218"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p998775410323">If the input script contains QUALIFY as an ALIAS before the FROM clause, the DSC will not migrate the statement and copy the input statement verbatim.</p>
</div></div>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p75094511376"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b13363714863226">Input: Order of Clauses</strong><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b13339847103226"> with QUALIFY as an ALIAS before the FROM clause</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen4374154012546"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span>
<span class="w"> </span><span class="o">*</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="n">table1</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">abc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span>
<span class="w"> </span><span class="k">SELECT</span>
<span class="w"> </span><span class="n">col1</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">qualify</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="k">TABLE</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">col1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">5</span>
<span class="w"> </span><span class="p">)</span>
<span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_p24051240105419"><strong id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_b373014293558">Output</strong></p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001819416169__en-us_topic_0000001706223997_en-us_topic_0000001434630665_screen940924011542"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span>
<span class="w"> </span><span class="o">*</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="n">table1</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">abc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span>
<span class="w"> </span><span class="k">SELECT</span>
<span class="w"> </span><span class="n">col1</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">qualify</span>
<span class="w"> </span><span class="k">FROM</span>
<span class="w"> </span><span class="k">TABLE</span>
<span class="w"> </span><span class="k">WHERE</span>
<span class="w"> </span><span class="n">col1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">5</span>
<span class="w"> </span><span class="p">)</span>
<span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_16_0087.html">SELECT</a></div>
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