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belongs_to through associations
...ave a :through option. You're better off caching the question_id on Choice and adding a unique index to the table (especially because validates_uniqueness_of is prone to race conditions).
If you're paranoid, add a custom validation to Choice that confirms that the answer's question_id matches, but ...
Multiple Indexes vs Multi-Column Indexes
I've just been adding an Index to a table in SQL Server 2005 and it got me thinking. What is the difference between creating 1 index and defining multiple columns over having 1 index per column you want to index.
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What is this operator in MySQL?
I'm working on code written by a previous developer and in a query it says,
9 Answers
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Spring JPA selecting specific columns
... answered Feb 25 '14 at 7:43
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What does %~d0 mean in a Windows batch file?
...h to the bat-file itself, %1 is the first argument after, %2 is the second and so on.
Since the arguments are often file paths, there is some additional syntax to extract parts of the path. ~d is drive, ~p is the path (without drive), ~n is the file name. They can be combined so ~dp is drive+path.
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Insert a line at specific line number with sed or awk
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mac users: with homebrew, brew install gnu-sed and then use this with gsed
– cwd
Jan 10 '15 at 17:58
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Ternary operator in AngularJS templates
...select either the property with name true or the property with name false, and return the associated value.
E.g.,
<li class="{{{true: 'myClass1 myClass2', false: ''}[$first]}}">...</li>
or
<li ng-class="{true: 'myClass1 myClass2', false: ''}[$first]">...</li>
$first is s...
Best programming aids for a quadriplegic programmer
... the heading of, "There, but for the grace of God, go you or I." This is brand new territory for me so I'm asking for some serious help here.
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How can I use map and receive an index as well in Scala?
Is there any List/Sequence built-in that behaves like map and provides the element's index as well?
8 Answers
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How do you show animated GIFs on a Windows Form (c#)
...atever properties (for instance progress bar or percentage) can be updated and animation can be updated with Application.DoEvents()
– Do-do-new
Sep 4 '17 at 9:02
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