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How to implement a unique index on two columns in rails
I have a table and I'm trying to add a unique index on two columns. Those columns are also indexed. So my question is if I just can remove the indexes who were just for one column or if I have to use all three indexes:
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What is the difference between syntax and semantics in programming languages?
What is the difference between syntax and semantics in programming languages (like C, C++)?
10 Answers
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Getting distance between two points based on latitude/longitude
I tried implementing this formula: http://andrew.hedges.name/experiments/haversine/
The aplet does good for the two points I am testing:
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Best way to center a on a page vertically and horizontally? [duplicate]
Best way to center a <div> element on a page both vertically and horizontally?
30 Answers
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Catch Ctrl-C in C
How does one catch Ctrl + C in C?
9 Answers
9
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Heroku NodeJS http to https ssl forced redirect
I have an application up and running on heroku with express on node with https,. How do I identify the protocol to force a redirect to https with nodejs on heroku?
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Android: How can I pass parameters to AsyncTask's onPreExecute()?
I use an AsyncTask for loading operations that I implemented as an inner class.
4 Answers
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Template default arguments
If I am allowed to do the following:
4 Answers
4
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Is there an easy way to request a URL in python and NOT follow redirects?
Looking at the source of urllib2 it looks like the easiest way to do it would be to subclass HTTPRedirectHandler and then use build_opener to override the default HTTPRedirectHandler, but this seems like a lot of (relatively complicated) work to do what seems like it should be pretty simple.
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Submit HTML form on self page
I want an HTML form to submit to itself. How do I use the action attribute?
5 Answers
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