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Lu, Huayi e6fa411af0 DWS DEV 830.201 version 
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 07:24:04 +00:00

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<a name="EN-US_TOPIC_0000001233430167"></a><a name="EN-US_TOPIC_0000001233430167"></a>
<h1 class="topictitle1">UPDATE</h1>
<div id="body8662426"><div class="section" id="EN-US_TOPIC_0000001233430167__s1a2f5c9584124c2787f5f4408f5ccb66"><h4 class="sectiontitle">Function</h4><p id="EN-US_TOPIC_0000001233430167__p47991831151819"><strong id="EN-US_TOPIC_0000001233430167__b9786101010213">UPDATE</strong> updates data in a table. <strong id="EN-US_TOPIC_0000001233430167__b842352706202423">UPDATE</strong> changes the values of the specified columns in all rows that satisfy the condition. The <strong id="EN-US_TOPIC_0000001233430167__b842352706182511">WHERE</strong> clause clarifies conditions. The columns to be modified need be mentioned in the <strong id="EN-US_TOPIC_0000001233430167__b842352706202429">SET</strong> clause; columns not explicitly modified retain their previous values.</p>
</div>
<div class="section" id="EN-US_TOPIC_0000001233430167__sdfe63777894c4e01bab369b693dbdacb"><h4 class="sectiontitle">Precautions</h4><ul id="EN-US_TOPIC_0000001233430167__uaee80a6a1bf742568230ddf9ad6e49c2"><li id="EN-US_TOPIC_0000001233430167__lac3c30c84b534f98a4214a06a68e8924">You must have the <strong id="EN-US_TOPIC_0000001233430167__b9851312145311">UPDATE</strong> permission on a table to be updated.</li><li id="EN-US_TOPIC_0000001233430167__l09d3602cd59948cea00708fc70fa4bc4">You must have the <strong id="EN-US_TOPIC_0000001233430167__b59758784145311">SELECT</strong> permission on all tables involved in the expressions or conditions.</li><li id="EN-US_TOPIC_0000001233430167__l43dc8ebcd2aa4e4892bad670b742c525">The distribution column of a table cannot be modified.</li><li id="EN-US_TOPIC_0000001233430167__l227c40ae71a3403fa449ae13ef91d32b">For column-store tables, the <strong id="EN-US_TOPIC_0000001233430167__en-us_topic_0058966033_b842352706173053">RETURNING</strong> clause is currently not supported.</li><li id="EN-US_TOPIC_0000001233430167__le52a0eb9737a408a99ebba16cf4dc21b">Column-store tables do not support non-deterministic update. If you update data in one row with multiple rows of data in a column-store table, an error is reported.</li><li id="EN-US_TOPIC_0000001233430167__l087d5d3bbb404eb488ede8cba7c5032d">Memory space that records update operations in column-store tables is not reclaimed. You need to clean it by executing <strong id="EN-US_TOPIC_0000001233430167__b842352706202224">VACUUM FULL table_name</strong>.</li><li id="EN-US_TOPIC_0000001233430167__li118521514115">You are not advised to create a table that needs to be frequently updated as a replication table.</li><li id="EN-US_TOPIC_0000001233430167__li1293161751418">Column-store tables support lightweight <strong id="EN-US_TOPIC_0000001233430167__b532516150409">UPDATE</strong> operations. Lightweight <strong id="EN-US_TOPIC_0000001233430167__b7508105334013">UPDATE</strong> operations only rewrite the updated columns to reduce space usage. Lightweight <strong id="EN-US_TOPIC_0000001233430167__b0915154015619">UPDATE</strong> for column-store tables is controlled by GUC parameter <strong id="EN-US_TOPIC_0000001233430167__b17244937131011">enable_light_colupdate</strong>.</li><li id="EN-US_TOPIC_0000001233430167__li133789052616">Column-store lightweight <strong id="EN-US_TOPIC_0000001233430167__b0643517121411">UPDATE</strong> is unavailable and automatically changes to the regular <strong id="EN-US_TOPIC_0000001233430167__b117448561159">UPDATE</strong> operation in the following scenarios: updating an index column, updating a primary key column, updating a partition column, updating a PCK column, and online scaling.</li></ul>
</div>
<div class="section" id="EN-US_TOPIC_0000001233430167__sb1017ffcd4054832899a482a7e034a0c"><h4 class="sectiontitle">Syntax</h4><div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__se715fd136ee048869801d7c99ba12c48"><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">UPDATE</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">ONLY</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="k">table_name</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="k">alias</span><span class="w"> </span><span class="p">]</span>
<span class="k">SET</span><span class="w"> </span><span class="err">{</span><span class="k">column_name</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="err">{</span><span class="w"> </span><span class="n">expression</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="k">DEFAULT</span><span class="w"> </span><span class="err">}</span><span class="w"> </span>
<span class="w"> </span><span class="o">|</span><span class="p">(</span><span class="w"> </span><span class="k">column_name</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="err">{</span><span class="p">(</span><span class="w"> </span><span class="err">{</span><span class="w"> </span><span class="n">expression</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="k">DEFAULT</span><span class="w"> </span><span class="err">}</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">)</span><span class="w"> </span><span class="o">|</span><span class="n">sub_query</span><span class="w"> </span><span class="err">}}</span><span class="p">[,</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">from_list</span><span class="p">]</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">condition</span><span class="w"> </span><span class="p">]</span>
<span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="n">RETURNING</span><span class="w"> </span><span class="err">{</span><span class="o">*</span><span class="w"> </span>
<span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="err">{</span><span class="n">output_expression</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">output_name</span><span class="w"> </span><span class="p">]</span><span class="err">}</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="err">}</span><span class="p">];</span>
<span class="k">where</span><span class="w"> </span><span class="n">sub_query</span><span class="w"> </span><span class="n">can</span><span class="w"> </span><span class="n">be</span><span class="p">:</span>
<span class="k">SELECT</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">ALL</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="k">DISTINCT</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">ON</span><span class="w"> </span><span class="p">(</span><span class="w"> </span><span class="n">expression</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">)</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="p">]</span>
<span class="err">{</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="err">{</span><span class="n">expression</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">output_name</span><span class="w"> </span><span class="p">]</span><span class="err">}</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="err">}</span>
<span class="p">[</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">from_item</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">]</span>
<span class="p">[</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">condition</span><span class="w"> </span><span class="p">]</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="n">grouping_element</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">]</span>
<span class="p">[</span><span class="w"> </span><span class="k">HAVING</span><span class="w"> </span><span class="n">condition</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...]</span><span class="w"> </span><span class="p">]</span>
</pre></div></td></tr></table></div>
</div>
</div>
<div class="section" id="EN-US_TOPIC_0000001233430167__s67fecbc83a47497e8a4ce29413971b2f"><h4 class="sectiontitle">Parameter Description</h4><ul id="EN-US_TOPIC_0000001233430167__u1a5670de55274e72af6a556e7d08e2cf"><li id="EN-US_TOPIC_0000001233430167__lcdad2d9b3f9a4d04a7ec90f15d6ba8f1"><strong id="EN-US_TOPIC_0000001233430167__afd3debcb3d2a4d80b4e37752462962f6">table_name</strong><p id="EN-US_TOPIC_0000001233430167__a5f22c01e47794479bef5b0eeddcf991d">Name (optionally schema-qualified) of the table to be updated.</p>
<p id="EN-US_TOPIC_0000001233430167__abc1f6bff7ca8467e8dd3bbb410fbc3b0">Value range: an existing table name</p>
</li><li id="EN-US_TOPIC_0000001233430167__l9d81378151c840608c7f91620059e663"><strong id="EN-US_TOPIC_0000001233430167__a870e440c9dbc4c2b8d332416c636b5b7">alias</strong><p id="EN-US_TOPIC_0000001233430167__a849db2fd073941289d905ecac08ab8ac">Specifies the alias for the target table.</p>
<p id="EN-US_TOPIC_0000001233430167__a4047bf2bb850400982359fec570c4f9b">Value range: a string. It must comply with the naming convention.</p>
</li><li id="EN-US_TOPIC_0000001233430167__l5ccf116ab72a48ecb86ddf1a860dff6c"><strong id="EN-US_TOPIC_0000001233430167__a57d4ea2cbe1c43dc8924e636411e8f04">column_name</strong><p id="EN-US_TOPIC_0000001233430167__a335cd08518224e18a82edb2e60652a04">Renames a column.</p>
<p id="EN-US_TOPIC_0000001233430167__p5785204161917">You can refer to this column by specifying the table name and column name of the target table. Example:</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen23261036203013"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">foo</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">foo</span><span class="p">.</span><span class="n">col_name</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'GaussDB'</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__ab1c6da4da31f4ee1a1864a526ba61468">You can refer to this column by specifying the target table alias and the column name. For example:</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen18771144014305"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">foo</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">f</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">f</span><span class="p">.</span><span class="n">col_name</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'GaussDB'</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__aed1d342e836f44a0a286542a40e7c9bb">Value range: an existing column name</p>
</li><li id="EN-US_TOPIC_0000001233430167__l4db40ebeace24f2cb70e85120c655c52"><strong id="EN-US_TOPIC_0000001233430167__a2c53ba7740e64fd092bd40c847a98990">expression</strong><p id="EN-US_TOPIC_0000001233430167__ae5a2f1ff674f49d8b7580e7ee1ff402f">An expression or value to assign to the column.</p>
</li><li id="EN-US_TOPIC_0000001233430167__l0f2f1af228be4dacbb8a025911ae07c0"><strong id="EN-US_TOPIC_0000001233430167__a4e6d59a99d144da7ad466add88928200">DEFAULT</strong><p id="EN-US_TOPIC_0000001233430167__a34c0dcfbb1ff47d78823499714a7ee74">Sets the column to its default value.</p>
<p id="EN-US_TOPIC_0000001233430167__ad63c42c579374304bfcbc50a12730acf">The value is <strong id="EN-US_TOPIC_0000001233430167__b4871682812018">NULL</strong> if no specified default value has been assigned to it.</p>
</li><li id="EN-US_TOPIC_0000001233430167__lb9e73cc187ef4cb6b38a53f8d1b489f5"><strong id="EN-US_TOPIC_0000001233430167__a363818727d8347049f82a47f0bb6ba6d">sub_query</strong><p id="EN-US_TOPIC_0000001233430167__a8a25df2d564c4696b9f6fc2827ef00c9">Specifies a subquery.</p>
<p id="EN-US_TOPIC_0000001233430167__a297880e0a1834e6a8e168b7f406b758d">This command can be executed to update a table with information for other tables in the same database. For details about clauses in the <strong id="EN-US_TOPIC_0000001233430167__b9830037142810">SELECT</strong> statement, see <a href="dws_06_0238.html">SELECT</a>.</p>
</li><li id="EN-US_TOPIC_0000001233430167__l5f64009f66594eec8d3f71dcc2ecba45"><strong id="EN-US_TOPIC_0000001233430167__a8b8c331618d740b2ba581bf6e3710474">from_list</strong><p id="EN-US_TOPIC_0000001233430167__ad94597688fa44e88b2e880934b744bcb">A list of table expressions, allowing columns from other tables to appear in the <strong id="EN-US_TOPIC_0000001233430167__b842352706202814">WHERE</strong> condition and the update expressions. This is similar to the list of tables that can be specified in the <strong id="EN-US_TOPIC_0000001233430167__b5816462712018">FROM</strong> clause of a <strong id="EN-US_TOPIC_0000001233430167__b5371960212018">SELECT</strong> statement.</p>
<div class="notice" id="EN-US_TOPIC_0000001233430167__n951a3aaaf9ea4965971145ac8008132e"><span class="noticetitle"><img src="public_sys-resources/notice_3.0-en-us.png"> </span><div class="noticebody"><p id="EN-US_TOPIC_0000001233430167__a5593275208aa489d86c67c22e1936e92">Note that the target table must not appear in the <strong id="EN-US_TOPIC_0000001233430167__b842352706202919">from_list</strong>, unless you intend a self-join (in which case it must appear with an alias in the <strong id="EN-US_TOPIC_0000001233430167__b842352706202926">from_list</strong>).</p>
</div></div>
</li><li id="EN-US_TOPIC_0000001233430167__l248f693e1e66469daee4bbd9f4dfb60a"><strong id="EN-US_TOPIC_0000001233430167__ae847319e57bd457cb07c242bd889b52c">condition</strong><p id="EN-US_TOPIC_0000001233430167__afde6a4043e2f4bfbb283e05df496d4a7">An expression that returns a value of type <strong id="EN-US_TOPIC_0000001233430167__b842352706202756"><span id="EN-US_TOPIC_0000001233430167__text82091522142419">boolean</span></strong>. Only rows for which this expression returns <strong id="EN-US_TOPIC_0000001233430167__b6600162562412">true</strong> are updated.</p>
</li><li id="EN-US_TOPIC_0000001233430167__le527c960b1b7463f8aa4e7fa516cb543"><strong id="EN-US_TOPIC_0000001233430167__a9d3699f1dac54c3383d46190f63eee40">output_expression</strong><p id="EN-US_TOPIC_0000001233430167__abc1aa70972a94d6593cc5af155fdfcd7">An expression to be computed and returned by the <strong id="EN-US_TOPIC_0000001233430167__b842352706203022">UPDATE</strong> command after each row is updated.</p>
<p id="EN-US_TOPIC_0000001233430167__a783627a3e86d4fa989873ab04ac92eea">Value range: The expression can use any column names of the table named by <strong id="EN-US_TOPIC_0000001233430167__b842352706203054">table_name</strong> or table(s) listed in <strong id="EN-US_TOPIC_0000001233430167__b842352706203059">FROM</strong>. Write * to return all columns.</p>
</li><li id="EN-US_TOPIC_0000001233430167__l50900bdd5e6243a38e871cd65d3065cc"><strong id="EN-US_TOPIC_0000001233430167__a3e10a0b55c244aea8b5e1ec85ac4207b">output_name</strong><p id="EN-US_TOPIC_0000001233430167__a278e5c0e25384003a850a285204b0a83">A name to use for a returned column.</p>
</li></ul>
</div>
<div class="section" id="EN-US_TOPIC_0000001233430167__sb15aa3fbbda8421486c4dc8bc0566c5f"><h4 class="sectiontitle">Examples</h4><p id="EN-US_TOPIC_0000001233430167__p3204123614915">Create the <strong id="EN-US_TOPIC_0000001233430167__b16397349358">reason</strong> table:</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen13386638175310"><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">DROP</span><span class="w"> </span><span class="k">TABLE</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="n">reason</span><span class="p">;</span>
<span class="k">CREATE</span><span class="w"> </span><span class="k">TABLE</span><span class="w"> </span><span class="n">reason</span>
<span class="p">(</span>
<span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="nb">int</span><span class="p">,</span>
<span class="w"> </span><span class="n">r_reason_desc</span><span class="w"> </span><span class="nb">char</span><span class="p">(</span><span class="mi">20</span><span class="p">),</span>
<span class="w"> </span><span class="n">r_reason_id</span><span class="w"> </span><span class="nb">char</span><span class="p">(</span><span class="mi">20</span><span class="p">)</span>
<span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">VALUES</span><span class="w"> </span><span class="p">(</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s1">'2'</span><span class="p">,</span><span class="w"> </span><span class="s1">'3'</span><span class="p">);</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__p11771119191717">Update the values of all records.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen1230497151819"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__p194143512615">If the <strong id="EN-US_TOPIC_0000001233430167__b14693172110269">WHERE</strong> clause is not included, all <strong id="EN-US_TOPIC_0000001233430167__b15757934182617">r_reason_sk</strong> values are updated.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen933181985512"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">100</span><span class="p">;</span>
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</div>
<p id="EN-US_TOPIC_0000001233430167__p7414125152615">Redefine <strong id="EN-US_TOPIC_0000001233430167__b1480831217276">r_reason_sk</strong> whose <strong id="EN-US_TOPIC_0000001233430167__b426219773513">r_reason_desc</strong> is <strong id="EN-US_TOPIC_0000001233430167__b244152713357">reason2</strong> in the <strong id="EN-US_TOPIC_0000001233430167__b424153113358">reason</strong> table.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen157501249419"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">5</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">r_reason_desc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'reason2'</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__p1141412510263">Redefine <strong id="EN-US_TOPIC_0000001233430167__b146551342133516">r_reason_sk</strong> whose value is <strong id="EN-US_TOPIC_0000001233430167__b6770174153618">2</strong> in the <strong id="EN-US_TOPIC_0000001233430167__b1537131183612">reason</strong> table.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen1961932212813"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">100</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001233430167__p16414259269">Redefine the course IDs whose <strong id="EN-US_TOPIC_0000001233430167__b136241818361">r_reason_sk</strong> is greater than 2 in the <strong id="EN-US_TOPIC_0000001233430167__b914452712364">reason</strong> table.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen20151104372311"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">201</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="mi">2</span><span class="p">;</span>
</pre></div></td></tr></table></div>
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<p id="EN-US_TOPIC_0000001233430167__p64141654260">You can run an <strong id="EN-US_TOPIC_0000001233430167__b951462763814">UPDATE</strong> statement to update multiple columns by specifying multiple values in the <strong id="EN-US_TOPIC_0000001233430167__b443013514382">SET</strong> clause. For example:</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001233430167__screen204238504232"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">UPDATE</span><span class="w"> </span><span class="n">reason</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="n">r_reason_sk</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">5</span><span class="p">,</span><span class="w"> </span><span class="n">r_reason_desc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'reason5'</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">r_reason_id</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s1">'fourth'</span><span class="p">;</span><span class="w"> </span>
</pre></div></td></tr></table></div>
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<div>
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<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_06_0227.html">DML Syntax</a></div>
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