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“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
...ON DUPLICATE KEY UPDATE.
If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. But the statement won't generate an error. It generates a warning instead. These cases include:
Inserting a duplicate key in columns with PRIMARY KEY or UNIQUE constrain...
Simple calculations for working with lat/lon and km distance?
...long coordinates are expressed in degrees, while the cos function in most (all?) languages typically accepts radians, therefore a degree to radians conversion is needed.
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婚庆O2O：领跑的企业也就只走到B轮 - 资讯 - 清泛网 - 专注C/C++及内核技术
...意思，很好玩？然并卵，怎么赚钱呐？如果不能解决这个问题，能叫商业创业吗？又不是过家家，自己嗨就行。当然如果只是闲着没事儿，想为爱晒幸福、秀恩爱的新人们多提供一些渠道，活着到也无妨。只是看你们撑的这么辛...
Chrome DevTools Devices does not detect device when plugged in
...s://developers.google.com/chrome-developer-tools/docs/remote-debugging
Install Windows USB driver http://developer.samsung.com/android/tools-sdks/Samsung-Android-USB-Driver-for-Windows
Install Android SDK http://developer.android.com/sdk/index.html
Install Android SDK Platform-tools http://developer...
Sending emails with Javascript
...ta of your SMTP server, It's best to do it on the server side with Node or PHP, thanks equally
– jcarlosweb
Nov 26 '18 at 13:49
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What is the difference between an Azure Web Site and an Azure Web Role
...pps (formerly Web Sites):
Ability to run elevated startup scripts to install apps, modify registry settings, install performance counters, fine-tune IIS, etc.
Ability to split an app up into tiers (maybe Web Role for front end, Worker Role for backend processing) and scale independently
Ability to...
Regular expression to match DNS hostname or IP Address?
...o be escaped with \.
ValidHostnameRegex is valid as per RFC 1123. Originally, RFC 952 specified that hostname segments could not start with a digit.
http://en.wikipedia.org/wiki/Hostname
The original specification of
hostnames in RFC
952,
mandated that labels could not start
with a d...
Convert HTML to PDF in .NET
...e wkhtmltopdf solutions on my project and had a bunch of hurdles.
I personally would avoid using wkhtmltopdf - based solutions on Hosted Enterprise applications for the following reasons.
First of all wkhtmltopdf is C++ implemented not C#, and you will
experience various problems embedding it wit...
jQuery returning “parsererror” for ajax request
...
I encountered this problem when my php script had an error, and was returning non-JSON data - a useful suggestion to disable dataType indeed!
– Sharadh
May 14 '14 at 19:18
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scala vs java, performance and memory? [closed]
...y easy to use enormous amounts of memory without realizing it. This is usually very powerful, but occasionally can be annoying. For example, suppose you have an array of strings (called array), and a map from those strings to files (called mapping). Suppose you want to get all files that are in t...