Blog.XiaoMing.Xyz
参考代码1:根据a.日期，和b表日期比较，遍历（逐条数据查找b.日期）只要是小于等于a.日期的收入数据，就累加求和。
<span class="token keyword">select</span> a<span class="token punctuation">.</span>日期<span class="token punctuation">,</span>
<span class="token punctuation">(</span>
<span class="token keyword">select</span> <span class="token function">sum</span><span class="token punctuation">(</span>b<span class="token punctuation">.</span>卖茶叶蛋收入<span class="token punctuation">)</span> <span class="token keyword">as</span> 累加 <span class="token keyword">from</span>
<span class="token punctuation">[</span>sheet1$a1<span class="token punctuation">:</span>b13<span class="token punctuation">]</span> b <span class="token keyword">where</span> b<span class="token punctuation">.</span>日期<span class="token operator"><=</span>a<span class="token punctuation">.</span>日期
<span class="token punctuation">)</span> <span class="token keyword">as</span> 累加
<span class="token keyword">from</span>
<span class="token punctuation">[</span>sheet1$a1<span class="token punctuation">:</span>b13<span class="token punctuation">]</span> a
参考代码2：a.日期对比b表日期，只要是b.日期小于或等于a.日期的数据都分成一组，然后求和.
<span class="token keyword">select</span> a<span class="token punctuation">.</span>日期<span class="token punctuation">,</span><span class="token function">sum</span><span class="token punctuation">(</span>b<span class="token punctuation">.</span>卖茶叶蛋收入<span class="token punctuation">)</span> <span class="token keyword">as</span> 累加 <span class="token keyword">from</span>
<span class="token punctuation">[</span>sheet1$a1<span class="token punctuation">:</span>b13<span class="token punctuation">]</span> a
inner <span class="token keyword">join</span>
<span class="token punctuation">[</span>sheet1$a1<span class="token punctuation">:</span>b13<span class="token punctuation">]</span> b
on
a<span class="token punctuation">.</span>日期<span class="token operator">>=</span>b<span class="token punctuation">.</span>日期
<span class="token keyword">group</span> by a<span class="token punctuation">.</span>日期
