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Rails find_or_create_by more than one attribute?
There is a handy dynamic attribute in active-record called find_or_create_by:
5 Answers
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Executing JavaScript without a browser?
...n on the topic, but if you want direct links, here they are:
You can install Rhino as others have pointed out. This post shows an easy way to get it up and running and how to alias a command to invoke it easily
If you're on a Mac, you can use JavaScriptCore, which invokes WebKit's JavaScript engin...
The best way to remove duplicate values from NSMutableArray in Objective-C?
...etWithArray:array]; You can then get back an array via array = [orderedSet allObjects]; or just use NSOrderedSets instead of NSArray in the first place.
– Regexident
May 14 '13 at 9:40
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submitting a GET form with query string params and hidden params disappear
...the question mark and the parameters, and then cross one's fingers to hope all browsers would leave that URL as it (and validate that the server understands it too). But I'd never rely on that.
By the way: it's not different for non-hidden form fields. For POST the action URL could hold a query stri...
What is “callback hell” and how and why does RX solve it?
... clear definition together with a simple example that explains what is a "callback hell" for someone who does not know JavaScript and node.js ?
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What does cmd /C mean? [closed]
...iable expansion using ! as the
delimiter. For example, /V:ON would allow !var! to expand the
variable var at execution time. The var syntax expands variables
at input time, which is quite a different thing when inside of a FOR
loop.
/V:OFF Disable delayed environmen...
SQL WITH clause example [duplicate]
...roduced by Oracle in the Oracle 9i release 2 database. The SQL WITH clause allows you to give a sub-query block a name (a process also called sub-query refactoring), which can be referenced in several places within the main SQL query. The name assigned to the sub-query is treated as though it was an...
How to go back to previous opened file in Vim? [duplicate]
...ve gone deep down the hierarchy of files by typing multiple gf, vim stores all the files in numbered buffers
Then following command will take you to the nth file in a buffer. (n = 1,2,3,..)
:e#n
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ON_COMMAND_RANGE 用法 - C/C++ - 清泛网 - 专注C/C++及内核技术
ON_COMMAND_RANGE 用法申明消息宏 + 回调函数模型，其他没什么好解释的。BEGIN_MESSAGE_MAP(CxxDialog, CDialog)
ON_COMMAND_RANGE(IDC_BUTTON_1, IDC_BUTTON_ALL, OnButtonClick)
END_MESSAGE_MAP()
afx_msg void OnButtonClick(UINT nID);ON_COMMAND_RANGE, MFC
【天气API】对接国内免费好用的天气API - App应用开发 - 清泛IT社区，为创新赋能！
...ather/weatherInfo?key=【你的_API_KEY】8&city=110000&extensions=all
复制代码
阿里云也有天气API。中国天气 weather.com.cn 虽然很权威，但是不对外提供API，网上的多数链接都失效了，不考虑。
优先选择高德。
参考：https://zhuanlan.z...