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Find difference between timestamps in seconds in PostgreSQL
I have a table in PostgreSQL 8.3 with 2 timestamp columns. I would like to get the difference between these timestamps in seconds. Could you please help me how to get this done?
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Index on multiple columns in Ruby on Rails
I'm implementing functionality to track which articles a user has read.
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MySQL: Selecting multiple fields into multiple variables in a stored procedure
Can I SELECT multiple columns into multiple variables within the same select query in MySQL?
3 Answers
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How to track child process using strace?
I used strace to attach to a process briefly. The process created 90 threads. When I found the offending thread, I had to tediously search for the parent thread, then the grandparent thread, and so on all the way to the root process.
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Nginx location priority
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From the HTTP core module docs:
Directives with the "=" prefix that match the query exactly. If found, searching stops.
All remaining directives with conventional strings. If this match used the "^~" prefix, searching stops.
Regular expressions,...
Scala: what is the best way to append an element to an Array?
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You can use :+ to append element to array and +: to prepend it:
0 +: array :+ 4
should produce:
res3: Array[Int] = Array(0, 1, 2, 3, 4)
It's the same as with any other implementation of Seq.
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How do I get the MIN() of two fields in Postgres?
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LEAST(a, b):
The GREATEST and LEAST functions select the largest or smallest value from a list of any number of expressions. The expressions must all be convertible to a common data type, which will be the type of the result (see Section 10.5 for details). NULL ...
Real-world applications of zygohistomorphic prepromorphisms
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Sharon Curtis and Shin-Cheng Mu have a Functional Pearl using zygomorphisms to find maximally dense segments (a generalization of maximum segment sums). Zygomorphisms are seemingly a good fit for sliding window problems once you are ...
Is there a way to use two CSS3 box shadows on one element?
I'm trying to replicate a button style in a Photoshop mock-up that has two shadows on it. The first shadow is an inner lighter box shadow (2px), and the second is a drop shadow outside the button (5px) itself.
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Select second last element with css
I already know of :last-child. But is there a way to select the div:
2 Answers
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