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Computed / calculated / virtual / derived columns in PostgreSQL
Does PostgreSQL support computed / calculated columns, like MS SQL Server? I can't find anything in the docs, but as this feature is included in many other DBMSs I thought I might be missing something.
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What is Common Gateway Interface (CGI)?
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CGI is an interface specification between a web server (HTTP server) and an executable program of some type that is to handle a particular request.
It describes how certain properties of that request should be communicated to the environment of that program and how the program sh...
How do I set the figure title and axes labels font size in Matplotlib?
... @AlexanderMcFarlane. I ran python -c 'import matplotlib as mpl; print(mpl.__version__); print("figure.titlesize" in mpl.rcParams.keys())'. Result is 1.5.1, True. 1) What version of matplotlib are you using? What version of Python? 2) Could it be a bug where for some reason it accepts str but not un...
What is the difference between tree depth and height?
... node having width 1, and an empty graph having width 0. mathworld.wolfram.com/GraphDiameter.html
– Daniel A.A. Pelsmaeker
Nov 26 '18 at 10:48
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How do I catch a PHP fatal (`E_ERROR`) error?
...o $e->getMessage(); // Call to a member function method() on string
}
https://3v4l.org/67vbk
Or you can use Throwable interface to catch all exceptions.
Example:
<?php
try {
undefinedFunctionCall();
} catch (Throwable $e) {
// Handle error
echo $e->getMe...
Static nested class in Java, why?
... edited May 23 '17 at 11:47
Community♦
111 silver badge
answered Oct 31 '08 at 13:47
matt bmatt b
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get size of json object
... check the size i.e. like that:
var data = {one : 1, two : 2, three : 3};
_.size(data);
//=> 3
_.keys(data);
//=> ["one", "two", "three"]
_.keys(data).length;
//=> 3
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How to convert IPython notebooks to PDF and HTML?
... and select File -> Download as -> HTML (.html) or run the following command:
jupyter nbconvert --to html notebook.ipynb
This will convert the Jupyter document file notebook.ipynb into the html output format.
Google Colaboratory is Google's free Jupyter notebook environment that require...
Finding index of character in Swift String
...ersome but using a wrapper to index by integers (see https://stackoverflow.com/a/25152652/669586) is dangerous because it hides the inefficiency of real indexing.
Note that Swift indexing implementation has the problem that indices/ranges created for one string cannot be reliably used for a differe...
How to determine whether an object has a given property in JavaScript
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Underscore.js or Lodash
if (_.has(x, "y")) ...
:)
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