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40 lines
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HTML
40 lines
2.0 KiB
HTML
<div class="m-bg">
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<h1>MySQL EXTRACT() 函数</h1>
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<h2>定义和用法</h2> <p>EXTRACT() 函数用于返回日期/时间的单独部分，比如年、月、日、小时、分钟等等。</p> <h3><b>语法</b></h3> <div class="code notranslate"><pre><code class="language-sql"><div> EXTRACT(unit FROM date)</div></code></pre></div> <p>date 参数是合法的日期表达式。unit 参数可以是下列的值：</p> <table class="reference notranslate">
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<tr><th align="left">Unit 值</th></tr>
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<tr><td>MICROSECOND</td></tr>
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<tr><td>SECOND</td></tr>
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<tr><td>MINUTE</td></tr>
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<tr><td>HOUR</td></tr>
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<tr><td>DAY</td></tr>
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<tr><td>WEEK</td></tr>
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<tr><td>MONTH</td></tr>
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<tr><td>QUARTER</td></tr>
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<tr><td>YEAR</td></tr>
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<tr><td>SECOND_MICROSECOND</td></tr>
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<tr><td>MINUTE_MICROSECOND</td></tr>
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<tr><td>MINUTE_SECOND</td></tr>
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<tr><td>HOUR_MICROSECOND</td></tr>
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<tr><td>HOUR_SECOND</td></tr>
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<tr><td>HOUR_MINUTE</td></tr>
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<tr><td>DAY_MICROSECOND</td></tr>
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<tr><td>DAY_SECOND</td></tr>
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<tr><td>DAY_MINUTE</td></tr>
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<tr><td>DAY_HOUR</td></tr>
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<tr><td>YEAR_MONTH</td></tr>
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</table>
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<h3>实例</h3> <p>假设我们有如下的 "Orders" 表：</p> <table class="reference notranslate">
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<tr>
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<th align="left">OrderId</th> <th align="left">ProductName</th> <th align="left">OrderDate</th> </tr>
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<tr>
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<td>1</td> <td>Jarlsberg Cheese</td> <td>2008-11-11 13:23:44.657</td> </tr>
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</table>
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<p>下面是 SELECT 语句：</p> <div class="code notranslate"><pre><code class="language-sql"><div> SELECT EXTRACT(YEAR FROM OrderDate) AS OrderYear,<br/> EXTRACT(MONTH FROM OrderDate) AS OrderMonth,<br/> EXTRACT(DAY FROM OrderDate) AS OrderDay,<br/> FROM Orders<br/> WHERE OrderId=1 </div></code></pre></div> <p>结果如下所示：</p> <table class="reference notranslate">
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<tr>
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<th align="left">OrderYear</th> <th align="left">OrderMonth</th> <th align="left">OrderDay</th> </tr>
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<tr>
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<td>2008</td> <td>11</td> <td>11</td> </tr>
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</table>
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<div class="text-center padding-10 margin-t-5">
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</div>
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</div> |