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How to set a default value for a datetime column to record creation time in a migration?

... has fields named created_at/created_on or updated_at/updated_on. Source - api.rubyonrails.org You don't need to do anything else except to have that column. share | improve this answer |...
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Assigning default value while creating migration file

...s_count, :integer, :null => false, :default => 0 ... and read Rails API share | improve this answer | follow | ...
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Passing arguments to angularjs filters

... Actually you can pass a parameter ( http://docs.angularjs.org/api/ng.filter:filter ) and don't need a custom function just for this. If you rewrite your HTML as below it'll work: <div ng:app> <div ng-controller="HelloCntl"> <ul> <li ng-repeat="friend in frien...
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python design patterns [closed]

...for their existence. It's nothing more than class Null(object): def __init__(self, *args, **kwargs): "Ignore parameters." return None def __call__(self, *args, **kwargs): "Ignore method calls." return self def __getattr__(self, mname): "Ignore...
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Is it possible to have multiple statements in a python lambda expression?

...Q. Can you put multiple statements in a lambda? A. No. But you don't actually need to use a lambda. You can put the statements in a def instead. i.e.: def second_lowest(l): l.sort() return l[1] map(second_lowest, lst) Q. Can you get the second lowest item from a lambda by sorting the ...
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从源代码剖析Mahout推荐引擎 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术

...,关于推荐算法的详细介绍,请参考文章:Mahout推荐算法API详解 7. 创建自己的推荐引擎构造器 有了上面的知识,我就清楚地知道了Mahout推荐引擎的原理和使用,我们就可以写一个自己的构造器,通过“策略模式”实现,算法...
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How to convert JSON to XML or XML to JSON?

...t in JSON format. Your answer was probably downvoted because it didn't actually answer the question. The OP wasn't asking if he should do the conversion, but rather if he could do it using tools already at his disposal. – David Brown Aug 1 '12 at 3:08 ...
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How to get the file extension in PHP? [duplicate]

...omething that's actually designed for what you want: pathinfo(): $path = $_FILES['image']['name']; $ext = pathinfo($path, PATHINFO_EXTENSION); share | improve this answer | ...
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Parse query string in JavaScript [duplicate]

...ne query value. I think a better abstraction is to return a JS object with all the name value pairs from the query string – Juan Mendes Sep 4 '12 at 23:37 11 ...
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Difference between Convert.ToString() and .ToString()

... var arg = Request.Params.Get("__EVENTARGUMENT"); string _arg = Convert.ToString(arg); _arg is not returing String.Empty when arg is null. why? – vml19 Mar 12 '12 at 3:33 ...