01 2022 档案
摘要:Finding null value in Dataset - DataRow.IsNull method vs ==DbNull.Value - c# 问题 What are the benefits of using the c# method DataRow.IsNull to determi
阅读全文
摘要:Is a GUID unique 100% of the time? 回答1 While each generated GUID is not guaranteed to be unique, the total number of unique keys (2128 or 3.4×1038) is
阅读全文
摘要:SQL Server discarding SPACE during GROUP BY 问题 Looks like SQL Server (tried on 2008 R2) is doing an RTRIM on columns in GROUP BY clause. Did anyone no
阅读全文
摘要:What is the benefit of using "SET XACT_ABORT ON" in a stored procedure? 回答1 SET XACT_ABORT ON instructs SQL Server to rollback the entire transaction
阅读全文
摘要:How can I get bootstrap version via javascript? 回答1 The version of each of Bootstrap's jQuery plugins can be accessed via the VERSION property of the
阅读全文
摘要:Twitter Bootstrap Carousel autoplay on load 回答1 you should do as the Twitter Bootstrap Documentation says about Carousel, so set the first Carousel sl
阅读全文
摘要:How do I view a single file's history in GitK? 回答1 To get the file history gitk <filename> To see the blame history in a gui, which may help you track
阅读全文
摘要:幂指函数_百度百科 (baidu.com) What is the value of limit x^(1/(x-1)) as x tends to 1?
阅读全文
摘要:主对角线(从左上角到右下角这条对角线)下方的元素全为零的行列式称为上三角行列式。一个n阶行列式若能通过变换,化为上三角行列式,则计算该行列式就很容易了。 通过初等变换,把普通的行列式转换为上三角行列式。 就可以通过外面的系数,乘以主对角线(从左上角到右下角这条对角线)上的元素,得到行列式的值。 需要
阅读全文
摘要:How to commit no change and new message? 回答1 There's rarely a good reason to do this, but the parameter is --allow-empty for empty commits (no files c
阅读全文
摘要:Get first day of week in SQL Server 回答1 To answer why you're getting a Monday and not a Sunday: You're adding a number of weeks to the date 0. What is
阅读全文
摘要:数学教授为什么仍然使用粉笔? 斯坦福大学几乎 100% 的数学系教师,依然使用粉笔和黑板授课。不仅老师们喜欢用粉笔,学生们也非常接受这种方式。 一个数学讲师曾经调查班上的51名同学,更喜欢黑板上的板书,还是用投影仪展示讲义?学生们一致反映:黑板更好。 粉笔和黑板的讲课方式,发明于19世纪初,至今已经
阅读全文
摘要:History Simplification 重现的repository在这里 https://github.com/ChuckTest/git-history-test 具体的讨论,参考这个,https://groups.google.com/g/git-users/c/n8Rj-YBUJEw A
阅读全文
摘要:直观理解贝叶斯公式 好多同学反应不理解贝叶斯公式,专门写一篇让大家直观的理解贝叶斯公式。 先来一个问题:一机器在良好状态生产合格产品几率是90%,在故障状态生产合格产品几率是30%,机器良好的概率是75%,若一日第一件产品是合格品,那么此日机器良好的概率是多少? 这里需要用到贝叶斯公式,贝叶斯公式一
阅读全文
摘要:Scorpion and the frog A scorpion asks a frog to carry him over a river. The frog is afraid of being stung, but the scorpion argues that if he did, bot
阅读全文
摘要:Excel 2007如何用countif()函数统计性别? Excel单列数据如何剔除重复值
阅读全文
摘要:Why Local Users and Groups is missing in Computer Management on Windows 10 Home? [closed] Windows 10 Home Edition does not have Local Users and Groups
阅读全文