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What is the difference between “INNER JOIN” and “OUTER JOIN”?
...ables, with a single column each, and data as follows:
A B
- -
1 3
2 4
3 5
4 6
Note that (1,2) are unique to A, (3,4) are common, and (5,6) are unique to B.
Inner join
An inner join using either of the equivalent queries gives the intersection of the two tables, i.e. the two r...
Loop through an array in JavaScript
...e seen this anti-pattern so many times.
Anti-pattern:
const numbers = [1,2,3,4,5], doubled = [];
numbers.forEach((n, i) => { doubled[i] = n * 2 });
Proper use case of map:
const numbers = [1,2,3,4,5];
const doubled = numbers.map(n => n * 2);
console.log(doubled);
Also, if you are ...
JavaScript hard refresh of current page
...
305
Try to use:
location.reload(true);
When this method receives a true value as argument, it w...
Python - use list as function parameters
How can I use a Python list (e.g. params = ['a',3.4,None] ) as parameters to a function, e.g.:
4 Answers
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Is gcc std::unordered_map implementation slow? If so - why?
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Get Selected index of UITableView
...%ld anyway.
– Jonathan Weinraub
Apr 3 at 15:12
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how to configure apache server to talk to HTTPS backend server?
...ectives :
SSLProxyEngine on
ProxyPass /primary/store https://localhost:9763/store/
ProxyPassReverse /primary/store https://localhost:9763/store/
See the doc for more detail.
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NULL vs nullptr (Why was it replaced?) [duplicate]
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answered Dec 11 '13 at 3:09
Joe ZJoe Z
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How to calculate time in hours between two dates in iOS
...weenDates = [date1 timeIntervalSinceDate:date2];
double secondsInAnHour = 3600;
NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;
See, the apple reference library http://developer.apple.com/library/mac/navigation/
or if you are using Xcode just select help/documentation from ...
How to make graphics with transparent background in R using ggplot2?
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