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How do I (or can I) SELECT DISTINCT on multiple columns?
I need to retrieve all rows from a table where 2 columns combined are all different. So I want all the sales that do not have any other sales that happened on the same day for the same price. The sales that are unique based on day and price will get updated to an active status.
...
Maximum value for long integer
...ong integers have unlimited precision. In Python 2, Integers will automatically switch to longs when they grow beyond their limit:
>>> import sys
>>> type(sys.maxsize)
<type 'int'>
>>> type(sys.maxsize+1)
<type 'long'>
for integers we have
maxint and maxsi...
How do I set a ViewModel on a window in XAML using DataContext property?
The question pretty much says it all.
5 Answers
5
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Pass props to parent component in React.js
...ase of direct parent-child relationship. When parent and child have potentially a lot of intermediaries, check this answer.
Other solutions are missing the point
While they still work fine, other answers are missing something very important.
Is there not a simple way to pass a child's props to...
Is it possible to figure out the parameter type and return type of a lambda?
...Andry that's a fundamental problem with function objects that have (potentially) multiple overloads of operator() not with this implementation. auto is not a type, so it can't ever be the answer to traits::template arg<0>::type
– Caleth
Jan 16 '18 at 12:1...
MySQL - length() vs char_length()
...() returns the length of the string measured in characters.
This is especially relevant for Unicode, in which most characters are encoded in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')
--> 3, 1
As you can see the E...
Can mustache iterate a top-level array?
...he');
var view = {test: 'div content', multiple : ['foo', 'bar'], multiple_2 : ['hello', 'world']};
var template = '<div>{{test}}</div><ul>{{#multiple}}<li>{{.}}</li>{{/multiple}}</ul><ul>{{#multiple_2}}<li>{{.}}</li>{{/multiple_2}}</ul>';...
How to delete items from a dictionary while iterating over it?
...--------------------------------------------------
Traceback (most recent call last):
File "<ipython console>", line 1, in <module>
RuntimeError: dictionary changed size during iteration
As stated in delnan's answer, deleting entries causes problems when the iterator tries to move on...
Javascript: best Singleton pattern [duplicate]
...lution found:
http://code.google.com/p/jslibs/wiki/JavascriptTips#Singleton_pattern
function MySingletonClass () {
if (arguments.callee._singletonInstance) {
return arguments.callee._singletonInstance;
}
arguments.callee._singletonInstance = this;
this.Foo = function () {
// ...
...
How do I split a string into an array of characters? [duplicate]
...]
For ES5, options are limited:
I came up with this function that internally uses MDN example to get the correct code point of each character.
function stringToArray() {
var i = 0,
arr = [],
codePoint;
while (!isNaN(codePoint = knownCharCodeAt(str, i))) {
arr.push(String.fromCode...