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SQL join: selecting the last records in a one-to-many relationship
Suppose I have a table of customers and a table of purchases. Each purchase belongs to one customer. I want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
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When is memoization automatic in GHC Haskell?
I can't figure out why m1 is apparently memoized while m2 is not in the following:
4 Answers
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What is the difference between customErrors and httpErrors?
What is the difference between the customErrors and httpErrors sections of the web.config file in ASP.NET MVC applications?
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Is there a version of JavaScript's String.indexOf() that allows for regular expressions?
...hat takes a regular expression instead of a string for the first first parameter while still allowing a second parameter ?
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How to move screen without moving cursor in Vim?
I recently discovered Ctrl + E and Ctrl + Y shortcuts for Vim that respectively move the screen up and down with a one line step, without moving the cursor .
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Create a custom View by inflating a layout?
I am trying to create a custom View that would replace a certain layout that I use at multiple places, but I am struggling to do so.
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How to replace an entire line in a text file by line number
...where I want a bash script to replace an entire line in a file.
The line number is always the same, so that can be a hard-coded variable.
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Javascript when to use prototypes
I'd like to understand when it is appropriate to use prototype methods in js. Should they always be used? Or are there cases where using them is not preferred and/or incurs a performance penalty?
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if A vs if A is not None:
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The statement
if A:
will call A.__nonzero__() (see Special method names documentation) and use the return value of that function. Here's the summary:
object.__nonzero__(self)
Called to implement truth value testing and the...
Does Java casting introduce overhead? Why?
...s there any overhead when we cast objects of one type to another? Or the compiler just resolves everything and there is no cost at run time?
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