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Difference between Select Unique and Select Distinct
...re trying to do. You can eliminate duplicates by choosing the appropriate union statement parameters.
the below query by itself will only provide distinct values
select col from table1
union
select col from table2
if you did want duplicates you would have to do
select col from table1
union ...
How to prevent ifelse() from turning Date objects into numeric objects
... My vote would be for a factor return object that had levels that were the union of the levels of true's and false's levels.
– IRTFM
Aug 28 '16 at 20:05
3
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Django connection to PostgreSQL: “Peer authentication failed”
...I am receiving when I try to get to my Django admin site. I had been using MySQL database no problem. I am new to PostgreSQL, but decided to switch because the host I ultimately plan to use for this project does not have MySQL.
...
技术人员如何创业《四》- 打造超强执行力团队 - 资讯 - 清泛网 - 专注C/C++...
技术人员如何创业《四》- 打造超强执行力团队好的团队是创业公司成功的必要因素之一。差劲的团队会导致整个团队没有战斗力，互相算计，只看到自己的利益，永远做不成一个好的产品。优秀 好的团队是创业公司成功的必...
Nginx缓存解决方案：SRCache - 更多技术 - 清泛网 - 专注C/C++及内核技术
....shared, key, value, expire)
end
return status
最后一个问题：如何判断缓存是否生效了？试试下面的命令：
shell> curl -v "http://foo.com/test?x=123&y=abc"
< X-SRCache-Fetch-Status: HIT
< X-SRCache-Store-Status: BYPASS
目前我主要用srcache来缓存一些接口...
Where and how is the _ViewStart.cshtml layout file linked?
... and ran this in the view engine ViewLocationFormats = ViewLocationFormats.Union(new string[] { "~/Inspinia/ExampleViews/{1}/{0}.cshtml" }).ToArray();. As a result, I had to add a copy of my _ViewStart.cshtml file to "~/Inspinia/ExampleViews", otherwise it was not picked up and no layout was set.
...
Windows下如何判断Win32 or x64？ - C/C++ - 清泛网 - 专注C/C++及内核技术
Windows下如何判断Win32 or x64？MSDN 里说，VC 有 3 个预处理常量，分别是 _WIN32，_WIN64，WIN32。这三个常量如何使用呢？看起来简单，其实是很困惑的。 在 Win3...MSDN 里说，VC 有 3 个预处理常量，分别是 _WIN32，_WIN64，WIN32。这三个...
pdf2htmlEX实现pdf转html - 开源 & Github - 清泛网 - 专注C/C++及内核技术
...景图像格式 (default: "png")
-o,--owner-password <string> 所有者密码 (为了加密文件)
-u,--user-password <string> 用户密码 (为了加密文件)
--no-drm <int> 覆盖文档的 DRM 设置 (default: 0)
--clean-tmp <int> 转换后删除临时文...
创业者如何发现开放却未知的秘密 - 资讯 - 清泛网 - 专注C/C++及内核技术
创业者如何发现开放却未知的秘密所谓开放却未知的秘密，其实就在用户手上，在用户口中，就在数据里面。最近几篇专栏一直在围绕需求这个主题展开，从第一篇的人性，第二篇的最美投资往往在眨眼之间，到第三篇的敬畏街...
What does Docker add to lxc-tools (the userspace LXC tools)?
...extremely fast, memory-cheap and disk-cheap.
This is provided by AUFS, a union filesystem that Docker depends on. You could set up AUFS yourself manually with LXC, but Docker uses it as a standard.
5) Logging: the standard streams (stdout/stderr/stdin) of each process container is collected an...