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Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
Selecting the first “n” items with jQuery
With Jquery, I need to select just the first "n" items from the page, for example the first 20 links instead of selecting all of them with the usual
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Unicode, UTF, ASCII, ANSI format differences
...ny other places, it means UTF-8. Properly, Unicode refers to the abstract character set itself, not to any particular encoding.
UTF-16: 2 bytes per "code unit". This is the native format of strings in .NET, and generally in Windows and Java. Values outside the Basic Multilingual Plane (BMP) are enc...
select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
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What does the “>” (greater-than sign) CSS selector mean?
...etimes mistakenly called the direct descendant combinator.1
That means the selector div > p.some_class only selects paragraphs of .some_class that are nested directly inside a div, and not any paragraphs that are nested further within.
An illustration:
div > p.some_class {
background:...
IntelliJ shortcut to show a popup of methods in a class that can be searched
... the list or highlight the desired element. Press Enter to navigate to the selected element.
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Trigger change() event when setting 's value with val() function
... easiest and best way to trigger change event when setting the value of select element.
5 Answers
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Using IntelliJ to amend git commit message
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Amend is supported: invoke "Commit Changes" and select the checkbox "Amend commit" in the Commit Dialog. Then press "Commit" button, and the commit will be amended to the previous one.
However, the support is limited:
you can't see the details of the commit being amend...
How to send password securely over HTTP?
...ded using
the RFC2045-MIME variant of Base64, except not limited to 76
char/line.
The authorization method and a space i.e. "Basic " is then
put before the encoded string.
source: Wikipedia: Authorization header
It might seem a bit complicated, but it is not.
There are plenty go...
How does virtual inheritance solve the “diamond” (multiple inheritance) ambiguity?
...virtual void eat(){ std::cout<<"EAT=>D";} };
int main(int argc, char ** argv){
A *a = new D();
a->eat();
delete a;
}
... that way the output is gonna be the correct one: "EAT=>D"
Virtual inheritance only solves the duplication of the grandfather!
BUT you still need ...