我个人感觉数据库这方面对于程序员来说很重要，无论是对于JAVA程序员还是DOTNET程序员以及其他编程人员来说都是必须掌握的。为了帮助大家更好的来回顾T-SQL，本人利用空闲的时间整理的一下T-SQL的语句和语法。希望对大家有用！
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<p>好的！我们先来看几个图像：</p>
<p><span style="FONT-FAMILY: 隶书; FONT-SIZE: 14pt"><strong><span style="COLOR: #ff00ff">棱形</span></strong></span><img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-7792938aaffebef69dffab25e1da6cef.jpg"><span style="FONT-FAMILY: 隶书; COLOR: #ff00ff; FONT-SIZE: 14pt"><strong>三角形<img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-69d170bab8622a7785f1c0a42cb5fc87.jpg">正方形</strong><img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-8c8dc03d084ddbbeb56b46c194d9b837.jpg"><strong>圆形</strong><img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-8e9788f7abb9d09577d29ba48db5fb21.jpg"></span><strong><span style="COLOR: #ff00ff"><span style="FONT-FAMILY: 隶书; FONT-SIZE: 14pt">矩</span><span style="FONT-FAMILY: 隶书; FONT-SIZE: 14pt">形</span></span></strong><span style="FONT-FAMILY: 隶书; COLOR: #ff00ff; FONT-SIZE: 14pt"><img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-7efd5c1426122016d4136e874c94b269.jpg"><strong>梯形<img alt="" src="https://beijingoptbbs.oss-cn-hangzhou.aliyuncs.com/jb/2426819-aab236c6df32ef5c1947161e2edc2a77.jpg"></strong></span></p>
<p>上面这些图形都是用T-SQL实现的，文章的最后我们一起来用T-SQL画出这些图形。</p>
<p>首先，我们开始回顾一下T-SQL的基本语法：</p><span style="FONT-FAMILY: 宋体; COLOR: #ff0000"><strong>函数</strong></span>
<p><strong><span style="TEXT-DECORATION: underline">abs(x)</span></strong><strong>：求绝对值</strong>；</p>
<div class="cnblogs_code"><pre>例： <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">abs</span>(<span style="COLOR: #808080">-</span><span style="COLOR: #800000; FONT-WEIGHT: bold">3</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">3</span></pre></div>
<p><strong><span style="TEXT-DECORATION: underline">sqrt(x)</span></strong>：<strong>求平方根</strong>；</p>
<div class="cnblogs_code"><pre>例： <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">sqrt</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">4</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">2.0</span></pre></div>
<p><strong><span style="TEXT-DECORATION: underline">rand([0])</span></strong>：<strong>返回</strong><strong>0~1</strong><strong>之间的随机float</strong><strong>值</strong>；</p>
<p><strong><span style="TEXT-DECORATION: underline">floor(X)</span></strong><strong>：返回小于或等于X</strong><strong>值的最大整数</strong>；</p>
<div class="cnblogs_code"><pre>例: <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">floor</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">34.5</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">34</span></pre></div>
<p><strong><span style="TEXT-DECORATION: underline">ceiling(X)</span></strong><strong>：返回大于或等于X</strong><strong>值的最小整数；</strong></p>
<div class="cnblogs_code"><pre>例： <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">ceiling</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">34.5</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">35</span></pre></div>
<p><strong><span style="TEXT-DECORATION: underline">round(x</span></strong><strong><span style="TEXT-DECORATION: underline">，length)</span></strong><strong>：四舍五入函数，length</strong><strong>为正，则对X</strong><strong>小数位数四舍五入，length</strong><strong>为负，则对X</strong><strong>从小数点左边length</strong><strong>位起四舍五入，若length</strong><strong>既为负数且其绝对值大于X</strong><strong>整数部分 </strong><strong>数字个数，则函数值为0；</strong></p>
<div class="cnblogs_code"><pre>例： <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">ROUND</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">63.567</span>, <span style="COLOR: #800000; FONT-WEIGHT: bold">1</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">63.600</span> <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">ROUND</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">63.567</span>, <span style="COLOR: #808080">-</span><span style="COLOR: #800000; FONT-WEIGHT: bold">1</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">60.000</span> <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">ROUND</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">63.567</span>, <span style="COLOR: #800000; FONT-WEIGHT: bold">0</span>) 值为：<span style="COLOR: #800000; FONT-WEIGHT: bold">64.000</span> <span style="COLOR: #0000ff">select</span> <span style="COLOR: #ff00ff">ROUND</span>(<span style="COLOR: #800000; FONT-WEIGHT: bold">63.567</s |
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