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SQL JOIN - WHERE clause vs. ON clause
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@JamesHutchison It's tough to make reliable performance generalizations based on observed behaviors like this. What was true one day tends to be wrong the next, because this is an implementation detail rather than documented behavior. Database teams are always look...
How to check for an active Internet connection on iOS or macOS?
...y via closures
let reachability = Reachability()!
reachability.whenReachable = { reachability in
if reachability.connection == .wifi {
print("Reachable via WiFi")
} else {
print("Reachable via Cellular")
}
}
reachability.whenUnreachable = { _ in
print("Not reachabl...
How to iterate through a DataTable
I need to iterate through a DataTable . I have an column there named ImagePath .
4 Answers
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Easiest way to detect Internet connection on iOS?
...through HTTPUrlConnection instantly fail if there is no connection available. This seems like completely sane behavior, and I was surprised to find NSURLConnection in iOS did not emulate it.
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How to use android emulator for testing bluetooth application?
...er settings of the virtual machine, Goto serialports -> Port 1 check Enable serial port select a port number
then select port mode as disconnected click ok. now, start virtual
machine. Under Devices -> USB Devices -> you can find your laptop
bluetooth listed. You can simply check t...
What is the appropriate HTTP status code response for a general unsuccessful request (not an error)?
...ul response and serve it to
subsequent clients even when clients may be able to make a successful
request.
I'll leave it to you to decide between 4xx and 5xx, but you should use an error status code.
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30岁之后，程序员该向什么方向发展？ - 杂谈 - 清泛网 - 专注C/C++及内核技术
...ools，用得人比较少。有一次我在Github上找到一个mootools的插件，很久没维护了。但是使用过程中发现一些问题，反复测试确认后，怀着忐忑的心情，我向原地址提交了commit，没想到他很快就合并了，并且向我表示感谢。当时的心...
Android Studio/Intellij Idea: “Table of Contents” for a class
...I have seen. One thing that has been annoying me though is this lack of "Table of Contents" for a class. I apologize for not knowing exactly what to call it. But what I am referring to is the dropdown menu in eclipse that lists all the methods, interfaces, classes and so on that are in that class fi...
LR性能指标解释 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...。
4.JMap。监控java程序是否有内存泄漏，需要配合eclipse插件或者MemoryAnalyzer来使用。
5.JProfiler。全面监控每个节点的CPU使用率、内存使用率、响应时间累计值、线程执行情况等，需要在JVM参数中进行配置。
6.Nmon。全面监控linux...
Understanding ibeacon distancing
... basic concept of how distancing with ibeacon (beacon/ Bluetooth-lowenergy/BLE) can work. Is there any true documentation on how far exactly an ibeacon can measure. Lets say I am 300 feet away...is it possible for an ibeacon to detect this?
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