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How do I find duplicates across multiple columns?
...TION BY s.name, s.city) AS qty
FROM stuff s
) t
WHERE t.qty > 1
ORDER BY t.name, t.city
While most recent RDBMS versions support count(*) over(partition by...) MySQL V 8.0 introduced "window functions", as seen below (in MySQL 8.0)
CREATE TABLE stuff(
id INTEGER NOT NULL
,name ...
Equivalent C++ to Python generator pattern
...to signal termination
In your trivial example, it's easy enough. Conceptually:
struct State { unsigned i, j; };
State make();
void next(State&);
bool isDone(State const&);
Of course, we wrap this as a proper class:
class PairSequence:
// (implicit aliases)
public std::iterat...
Types in MySQL: BigInt(20) vs Int(20)
...gInt , MediumInt , and Int are... it would seem obvious that they would allow for larger numbers; however, I can make an Int(20) or a BigInt(20) and that would make seem that it is not necessarily about size.
...
What is the optimal algorithm for the game 2048?
...ructures in which adjacent tiles are decreasing in value, but of course in order to merge, adjacent tiles need to be the same value. Therefore, the smoothness heuristic just measures the value difference between neighboring tiles, trying to minimize this count.
A commenter on Hacker News gave an int...
Reset Entity-Framework Migrations
... I used IgnoreChanges on the initial migration, but now I want to delete all my migrations and start with an initial migration with all of the logic.
...
Is explicitly closing files important?
In Python, if you either open a file without calling close() , or close the file but not using try - finally or the " with " statement, is this a problem? Or does it suffice as a coding practice to rely on the Python garbage-collection to close all files? For example, if one does this:
...
Why do we need a fieldset tag?
...entified categories.
Different browsers may display the default fieldset border in different ways. Cascading Style Sheets can be used to remove the border or change its appearance.
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What is the easiest/best/most correct way to iterate through the characters of a string in Java?
...
In Java 8 we can solve it as:
String str = "xyz";
str.chars().forEachOrdered(i -> System.out.print((char)i));
str.codePoints().forEachOrdered(i -> System.out.print((char)i));
The method chars() returns an IntStream as mentioned in doc:
Returns a stream of int zero-extending the cha...
Read environment variables in Node.js
...bles per project:
Create a .env file under the project directory and put all of your
variables there.
Add this line in the top of your application entry file:
require('dotenv').config();
Done. Now you can access your environment variables with process.env.ENV_NAME.
...
Iterating each character in a string using Python
...
If that seems like magic, well it kinda is, but the idea behind it is really simple.
There's a simple iterator protocol that can be applied to any kind of object to make the for loop work on it.
Simply implement an iterator that defines a next() method, and implement an __iter__ method on a c...