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What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
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To clarify on the "This is bad" - you could get all the wheels with 1 select (SELECT * from Wheel;), instead of N+1. With a large N, the pe...
How to print register values in GDB?
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edited Mar 30 '14 at 19:59
Millie Smith
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find() with nil when there are no records
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Yes, just do:
Challenge.find_by_id(10)
For Rails 4 and 5:
Challenge.find_by(id: 10)
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Can't connect Nexus 4 to adb: unauthorized
I have a Nexus 4 with Android 4.3 and I am trying to connect the device to a computer with Windows 7 64bit.
26 Answers
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How can you use optional parameters in C#?
... at a time when C# did not yet support optional parameters (i.e. before C# 4).
23 Answers
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How do I protect Python code? [closed]
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answered Nov 4 '08 at 12:00
Ned BatchelderNed Batchelder
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C# 4 default parameter values: How to assign a default DateTime/object value? [duplicate]
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edited May 24 '10 at 3:30
answered May 24 '10 at 3:24
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How do I extract a sub-hash from a hash?
...in other answers, but to sum them in one place:
x = {a: 1, b: 2, c: 3, d: 4}
# => {:a=>1, :b=>2, :c=>3, :d=>4}
x.slice(:a, :b)
# => {:a=>1, :b=>2}
x
# => {:a=>1, :b=>2, :c=>3, :d=>4}
x.except(:a, :b)
# => {:c=>3, :d=>4}
x
# => {:a=>1, :b=>...
Is it possible to specify a starting number for an ordered list?
...number to be 6. I found that this was supported (now deprecated) in HTML 4.01. In this specification they say that you can specify the starting integer by using CSS. (instead of the start attribute)
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Padding within inputs breaks width 100%
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Vega
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answered Dec 17 '12 at 16:29
Víctor Dieppa Ga...