大约有 41,000 项符合查询结果(耗时:0.0399秒) [XML]

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Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?

In multiple courses, books, and jobs, I have seen text fields defined as VARCHAR(255) as kind of the default for "shortish" text. Is there any good reason that a length of 255 is chosen so often, other than being a nice round number ? Is it a holdout from some time in the past when there was a go...
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Why doesn't C have unsigned floats?

...If C++ did support it, then you would be sometimes using an unsigned float and not realizing that your performance has just been killed. If C++ supported it then every floating point operation would need to be checked to see if it is signed or not. And for programs that do millions of floating poi...
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What's the difference between the 'ref' and 'out' keywords?

... The ref modifier means that: The value is already set and The method can read and modify it. The out modifier means that: The Value isn't set and can't be read by the method until it is set. The method must set it before returning. ...
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Routing for custom ASP.NET MVC 404 Error page

... Just add catch all route at the end of the routes table and display whatever page you want with it. See: How can i make a catch all route to handle '404 page not found' queries for ASP.NET MVC? share ...
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How to find Unused Amazon EC2 Security groups

...'m try to find a way to determine orphan security groups so I can clean up and get rid of them. Does anyone know of a way to discover unused security groups. ...
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PHP Composer update “cannot allocate memory” error (using Laravel 4)

... can fix the issue. Also you should be committing your composer.lock file and doing a composer install on a production environment which is less resource intensive. More details here: https://github.com/composer/composer/issues/1898#issuecomment-23453850 ...
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error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' — Miss

...ing to run mysql without passwords turned on... but whenever I ran the command 44 Answers ...
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How to use LINQ to select object with minimum or maximum property value

... Probably a little slower than just implementing IComparable and using Min (or a for loop). But +1 for a O(n) linqy solution. – Matthew Flaschen May 27 '09 at 6:07 4...
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Change “on” color of a Switch

I'm using a standard Switch control with the holo.light theme in a ICS app. 22 Answers ...
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How to use underscore.js as a template engine?

...'m trying to learn about new usages of javascript as a serverside language and as a functional language. Few days ago I heard about node.js and express framework. Then I saw about underscore.js as a set of utility functions. I saw this question on stackoverflow . It says we can use underscore.js a...