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Counting DISTINCT over multiple columns
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Too good suggestion. It avoided me to write unnecessary code to this.
– Avrajit Roy
Mar 9 '16 at 6:39
1
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How to find the mime type of a file in python?
Let's say you want to save a bunch of files somewhere, for instance in BLOBs. Let's say you want to dish these files out via a web page and have the client automatically open the correct application/viewer.
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Submit form using a button outside the tag
... cannot do this without javascript.
Here's what the spec says
The elements used to create controls generally appear inside a FORM
element, but may also appear outside of a FORM element declaration
when they are used to build user interfaces. This is discussed in the
section on intrinsic ...
Why does X[Y] join of data.tables not allow a full outer join, or a left join?
...quote from the data.table FAQ 1.11 What is the difference between X[Y] and merge(X, Y)?
X[Y] is a join, looking up X's rows using Y (or Y's key if it has one) as an index.
Y[X] is a join, looking up Y's rows using X (or X's key if it has one)
merge(X,Y) does both ways at the same time....
How do I change bash history completion to complete what's already on the line?
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Probably something like
# ~/.inputrc
"\e[A": history-search-backward
"\e[B": history-search-forward
or equivalently,
# ~/.bashrc
if [[ $- == *i* ]]
then
bind '"\e[A": history-search-backward'
bind '"\e[B": history-search-f...
Prevent browser caching of AJAX call result
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I use new Date().getTime(), which will avoid collisions unless you have multiple requests happening within the same millisecond:
$.get('/getdata?_=' + new Date().getTime(), function(data) {
console.log(data);
});
Edit: This answer is sever...
Google Chrome form autofill and its yellow background
I have design problem with Google Chrome and its form autofill function.
If Chrome remembers some login/password it changes a background color to a yellow one.
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How to debug .htaccess RewriteRule not working
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Enter some junk value into your .htaccess
e.g. foo bar, sakjnaskljdnas
any keyword not recognized by htaccess
and visit your URL. If it is working, you should get a
500 Internal Server Error
Internal Server Error
The ...
How to avoid .pyc files?
...e Python
interpreter, or by setting the
PYTHONDONTWRITEBYTECODE environment
variable before running the
interpreter. This setting is available
to Python programs as the
sys.dont_write_bytecode variable, and
Python code can change the value to
modify the interpreter’s behaviour.
U...
How do I determine if a port is open on a Windows server? [closed]
...:port on Unix systems) to see if the connection is refused, accepted, or timeouts.
On that latter test, then in general:
connection refused means that nothing is running on that port
accepted means that something is running on that port
timeout means that a firewall is blocking access
On Windo...