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<div class="section" id="select-index">
<span id="select"></span><h1>SELECT index<a class="headerlink" href="#select-index" title="Permalink to this headline">¶</a></h1>
<blockquote>
<div><div class="line-block">
<div class="line">可用版本： >= 1.0.0</div>
<div class="line">时间复杂度： O(1)</div>
</div>
</div></blockquote>
<p>切换到指定的数据库，数据库索引号 <code class="docutils literal"><span class="pre">index</span></code> 用数字值指定，以 <code class="docutils literal"><span class="pre">0</span></code> 作为起始索引值。</p>
<p>默认使用 <code class="docutils literal"><span class="pre">0</span></code> 号数据库。</p>
<div class="section" id="id1">
<h2>返回值<a class="headerlink" href="#id1" title="Permalink to this headline">¶</a></h2>
<p><code class="docutils literal"><span class="pre">OK</span></code></p>
</div>
<div class="section" id="id2">
<h2>代码示例<a class="headerlink" href="#id2" title="Permalink to this headline">¶</a></h2>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">redis</span><span class="o">></span> <span class="n">SET</span> <span class="n">db_number</span> <span class="mi">0</span> <span class="c1"># 默认使用 0 号数据库</span>
<span class="n">OK</span>
<span class="n">redis</span><span class="o">></span> <span class="n">SELECT</span> <span class="mi">1</span> <span class="c1"># 使用 1 号数据库</span>
<span class="n">OK</span>
<span class="n">redis</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">></span> <span class="n">GET</span> <span class="n">db_number</span> <span class="c1"># 已经切换到 1 号数据库，注意 Redis 现在的命令提示符多了个 [1]</span>
<span class="p">(</span><span class="n">nil</span><span class="p">)</span>
<span class="n">redis</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">></span> <span class="n">SET</span> <span class="n">db_number</span> <span class="mi">1</span>
<span class="n">OK</span>
<span class="n">redis</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">></span> <span class="n">GET</span> <span class="n">db_number</span>
<span class="s2">"1"</span>
<span class="n">redis</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="o">></span> <span class="n">SELECT</span> <span class="mi">3</span> <span class="c1"># 再切换到 3 号数据库</span>
<span class="n">OK</span>
<span class="n">redis</span><span class="p">[</span><span class="mi">3</span><span class="p">]</span><span class="o">></span> <span class="c1"># 提示符从 [1] 改变成了 [3]</span>
</pre></div>
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