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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... NULL is less efficient
In PostgreSQL, NOT IN is less efficient
In Oracle, all three methods are the same.
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See what has been installed via MacPorts
Is there a way to see all I have installed via MacPorts?
1 Answer
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Error handling principles for Node.js + Express.js applications?
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Error handling in Node.js is generally of the format A). Most callbacks return an error object as the first argument or null.
Express.js uses middleware and the middleware syntax uses B) and E) (mentioned below).
C) is bad practice if you ask me.
app.get('...
Is there any way to view the currently mapped keys in Vim?
Basically, I'd like to view all of the keys maps made in the current buffer by all of plugins, vimrc, etc, in the current buffer. Is there anyway to do this?
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MySQL 'create schema' and 'create database' - Is there any difference
... CREATE SCHEMA is a synonym for CREATE DATABASE as of MySQL 5.0.2.
this all goes back to an ANSI standard for SQL in the mid-80s.
That standard had a "CREATE SCHEMA" command, and it served to introduce
multiple name spaces for table and view names. All tables and views were
created within a "s...
Do fragments really need an empty constructor?
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Yes they do.
You shouldn't really be overriding the constructor anyway. You should have a newInstance() static method defined and pass any parameters via arguments (bundle)
For example:
public static final MyFragment newInstance(int title, String messa...
How to find available versions for a bower dependency
... command to get detailed info specific to a package. bower search prints all packages that has the query string as a substring.
– Yiling
Aug 29 '15 at 16:15
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Scala: What is the difference between Traversable and Iterable traits in Scala collections?
...ersables don't.
A Traversable has one abstract method: foreach. When you call foreach, the collection will feed the passed function all the elements it keeps, one after the other.
On the other hand, an Iterable has as abstract method iterator, which returns an Iterator. You can call next on an Ite...
Is there any way to delete local commits in Mercurial?
...y conflicts, test, and then push.
The strip command is useful when you really want to get rid of changesets that pollute the branch. In fact, if you're in this question's situation and you want to completely remove all "draft" change sets permanently, check out the top answer, which basically sugg...
ASP.NET MVC on IIS 7.5
..." in Framework64 for 64-bit Windows! that bit me in the *ss. I must've installed the 32 bit verion 4 or 5 times with no effect.
– Ben Lesh
Jan 4 '11 at 15:31
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