Recently seen PowerBI circle discussing the issue of maximum continuous range segment, that somebody largest attendance time, calculate someone's longest continuous punches and other issues, Zorro teacher gives the answer 10 times the performance. This issue also sparked some interest I vaguely remember the scenario window function previously seen Sqlserver of knowledge in this area, this weekend also spent a day to ponder over the pages again, very taste, and we intend in this Share it. Time is limited, only the first paper thrown issue, the next re-posted answers.
I strongly recommend this book, written by a foreigner Sqlserver the MVP, very exciting. Because of this read related books, he continued to recommend to the people around, doing data analysis, the best option is to do Sqlserver database, both storage and query than the ACCESS / Sqlite / MySQL database and so much good.
Sqlserver also has a free version Sqlserver Express, supports the full range of T-SQL queries, enough to replace these so-called free MySQL database.
Because Sqlserver database on more than just storage feature, which expands the window function, is a natural for the data analysis services.
In the database environment, easily handle one million level data, more than 60,000 data so the teacher Zorro 3 seconds to complete the test, very cruel, for as Sqlserver window function to handle, 6 million data, there is a moment of time (look at the specific time when the next test) is completed, only to spend extreme cruelty to describe.
The key is no need to type the formula hieroglyphics complete, this bible, no promotional value, does not conform to Microsoft father of enabling ordinary people can grasp the idea.
So here also come out of a topic, to achieve the requirements of a particular scene, if you really want to use a dead end one way, for example, frequently used functions in Excel can only hear in the community, you can not do it with VBA. Times change for the exam, so practice is still necessary, but time in the workplace, fast, simple and complete the tasks at hand, that is benevolent, as to how to achieve, many roads lead to Rome, why only certain method it.
Good use of the hands of a variety of tools, rather than the use of a tool excessively.
Chilling to delve into the abyss of a bottomless pit, in addition to these virtuoso and training institutions do bluffing, but really is not recommended in the actual workplace.
案例题目
题目1：数据差距
数据源是一系列的连续数字，中途有断开，最终需要加工出断开的数据区域。
题目2：数据岛
同样是上述的数据源，但这次是统计出各连续的数据区域片段，期望数据结构如下：
题目1和题目2即是佐罗老师他所引出的问题，统计各个连续时间段的区间，若需要最大次数这类的答案，只需将结构区减去开始区即可，更多实际的应用场景需要将开始区和结束区一同罗列出来。当然数据源还没有做分组处理，如上述的情况只是针对一次的数据统计，而不是实际上的多个用户各自的统计结果，在答案篇我尝试去测试，今天时间来不及，大家去思考时，不妨也增加难度加上多个用户的分析情况。如数据源如下：
结语
在笔者眼中，Sqlserver是难得的数据分析利器，性能强大，功能丰富，大家不妨先预习一下了解下Sqlserver窗口函数的知识，有兴趣的不妨也购买下本文提及的优秀图书。答案将在下期尽可能详尽地讲述。
关于Excel催化剂
Excel催化剂先是一微信公众号的名称，后来顺其名称，正式推出了Excel插件，插件将持续性地更新，更新的周期视本人的时间而定争取一周能够上线一个大功能模块。Excel催化剂插件承诺个人用户永久性免费使用！
Excel催化剂插件使用最新的布署技术，实现一次安装，日后所有更新自动更新完成，无需重复关注更新动态，手动下载安装包重新安装，只需一次安装即可随时保持最新版本！
Excel催化剂插件下载链接：https://pan.baidu.com/s/1Iz2_NZJ8v7C9eqhNjdnP3Q
取名催化剂，因Excel本身的强大，并非所有人能够立马享受到，大部分人还是在被Excel软件所虐的阶段，就是头脑里很清晰想达到的效果，而且高手们也已经实现出来，就是自己怎么弄都弄不出来，或者更糟的是还不知道Excel能够做什么而停留在不断地重复、机械、手工地在做着数据，耗费着无数的青春年华岁月。所以催生了是否可以作为一种媒介，让广大的Excel用户们可以瞬间点燃Excel的爆点，无需苦苦地挣扎地没日没夜的技巧学习、高级复杂函数的烧脑，最终走向了从入门到放弃的道路。
最后Excel功能强大，其实还需树立一个观点，不是所有事情都要交给Excel去完成，也不是所有事情Excel都是十分胜任的，外面的世界仍然是一个广阔的世界，Excel只是其中一枚耀眼的明星，还有其他更多同样精彩强大的技术、工具等。*Excel催化剂也将借力这些其他技术，让Excel能够发挥更强大的爆发！
关于Excel催化剂作者
姓名：李伟坚，从事数据分析工作多年（BI方向），一名同样在路上的学习者。
服务过行业：零售特别是鞋服类的零售行业，电商（淘宝、天猫、京东、唯品会）
技术路线从一名普通用户，通过Excel软件的学习，从此走向数据世界，非科班IT专业人士。
历经重重难关，终于在数据的道路上达到技术平原期，学习众多的知识不再太吃力，同时也形成了自己的一套数据解决方案（数据采集、数据加工清洗、数据多维建模、数据报表展示等）。
擅长技术领域：Excel等Office家族软件、VBA&VSTO的二次开发、Sqlserver数据库技术、Sqlserver的商业智能BI技术、Powerbi技术、云服务器布署技术等等。
2018 began his career made a major adjustment, from the original full-time job, turned freelance, no fixed income, temporarily on the road ahead is not clear, bitter return to full-time job, for Excel catalyst operations and development must be greatly affected (within the time could not maintain full-time job can not just put the results in a work published in time, the time outside of work is very limited, because he has thirty years of age, family responsibility).
And the majority of advocates with expectations: Excel catalyst has been able to run down, I have the benefit of the group were able to support ( multi-message encouragement, friend circle under forwarded the recommendation under small a reward and the most focused and where the company can and recommended recommended peers, so I can maximize the value of technology in your company to achieve a win-win (you can imagine how the data is preliminary consultant or small projects to develop forms of cooperation).