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SQL Joins Vs SQL Subqueries (Performance)?
...t query to be quicker, mainly because you have an equivalence and an explicit JOIN. In my experience IN is a very slow operator, since SQL normally evaluates it as a series of WHERE clauses separated by "OR" (WHERE x=Y OR x=Z OR...).
As with ALL THINGS SQL though, your mileage may vary. The spee...
How to prevent form resubmission when page is refreshed (F5 / CTRL+R)
I have a simple form that submits text to my SQL table. The problem is that after the user submits the text, they can refresh the page and the data gets submitted again without filling the form again. I could redirect the user to another page after the text is submitted, but I want users to stay on ...
Is an index needed for a primary key in SQLite?
When an integer column is marked as a primary key in an SQLite table, should an index be explicitly created for it as well? SQLite does not appear to automatically create an index for a primary key column, but perhaps it indexes it anyway, given its purpose? (I will be searching on that column all t...
Android - Emulator in landscape mode, screen does not rotate
When I switch to landscape mode ( NUMPAD 7 or CTRL + F11 ) the emulator rotates the screen to landscape orientation but the Android OS and none of the apps rotate. So everything is sitting sideways. Is there something in the AVD configuration that needs to be set in order for the device to rotate ...
Open URL under cursor in Vim with browser
I'm using Twitvim for the first time. Seeing all the URLs in there made me wonder, is there any way to open the URL under the cursor in your favorite browser or a specified one?
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Duplicate symbols for architecture x86_64 under Xcode
I now have the same question with above title but have not found the right answer yet. I got the error:
51 Answers
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How to construct a REST API that takes an array of id's for the resources
...d Dec 27 '10 at 20:04
Florin DumitrescuFlorin Dumitrescu
7,64833 gold badges3030 silver badges2929 bronze badges
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Difference between shadowing and overriding in C#?
...
Well inheritance...
suppose you have this classes:
class A {
public int Foo(){ return 5;}
public virtual int Bar(){return 5;}
}
class B : A{
public new int Foo() { return 1;} //shadow
public override int Bar() {return...
Scatterplot with marginal histograms in ggplot2
Is there a way of creating scatterplots with marginal histograms just like in the sample below in ggplot2 ? In Matlab it is the scatterhist() function and there exist equivalents for R as well. However, I haven't seen it for ggplot2.
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Fatal error: Maximum execution time of 30 seconds exceeded
I am downloading a JSON file from an online source and and when it runs through the loop I am getting this error:
16 Answer...