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How can I rename a database column in a Ruby on Rails migration?
...mething else or do nothing
end
end
For Rails 3.1 use:
While, the up and down methods still apply, Rails 3.1 receives a change method that "knows how to migrate your database and reverse it when the migration is rolled back without the need to write a separate down method".
See "Active Record...
CSS: How do I auto-resize an image to fit a 'div' container?
...ight: 100%;
}
.portrait {
height: 80px;
width: 30px;
}
.landscape {
height: 30px;
width: 80px;
}
.square {
height: 75px;
width: 75px;
}
Portrait Div
<div class="portrait">
<img src="http://i.stack.imgur.com/xkF9Q.jpg">
</div>
La...
Can I record/play macros in Visual Studio 2012/2013/2015/2017/2019?
...a few minutes ago I was horrified to discover VS2012's omission of macros, and you posted this 11 hours before I got here!
– Shaul Behr
Nov 13 '12 at 11:11
...
What are detached, persistent and transient objects in hibernate?
What are detached, persistent and transient objects in hibernate? Please explain with an example.
5 Answers
...
How do I move forward and backward between commits in git?
I am doing a git bisect and after arriving to the problematic commit, I am now trying to get a step forward/backward to make sure I am in the right one.
...
How do you enable “Enable .NET Framework source stepping”?
...
The PDBs for stepping through the source code are only posted for RTM and Service Packs. As such, when security update comes out and it modifies the dll you are trying to debug, it will cause source stepping to not work (that is, you'll get the "No source Available" with a greyed out "Browse t...
Actual meaning of 'shell=True' in subprocess
...y cmd.exe.
So invoking the shell invokes a program of the user's choosing and is platform-dependent. Generally speaking, avoid invocations via the shell.
Invoking via the shell does allow you to expand environment variables and file globs according to the shell's usual mechanism. On POSIX system...
Why doesn't String switch statement support a null case?
...wondering why the Java 7 switch statement does not support a null case and instead throws NullPointerException ? See the commented line below (example taken from the Java Tutorials article on switch ):
...
What requirement was the tuple designed to solve?
...urn, or when you want to key a dictionary off of two data rather than one, and so on.
Languages like F# which support tuple types natively provide a great deal of flexibility to their users; they are an extremely useful set of data types. The BCL team decided to work with the F# team to standardi...
What is the difference between Spring, Struts, Hibernate, JavaServer Faces, Tapestry?
...
Spring is an IoC container (at least the core of Spring) and is used to wire things using dependency injection. Spring provides additional services like transaction management and seamless integration of various other technologies.
Struts is an action-based presentation framework (...