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difference between primary key and unique key
...d on multiple columns, e.g. Primary key (CustomerID, ProductID). This is called composite primary key. This is to clarify the first point, as it might be take as it is (read one key => one column ) by new comer to sql : )
– ken
Apr 10 '14 at 13:53
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Java how to replace 2 or more spaces with single space in string and delete leading and trailing spa
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Try this:
String after = before.trim().replaceAll(" +", " ");
See also
String.trim()
Returns a copy of the string, with leading and trailing whitespace omitted.
regular-expressions.info/Repetition
No trim() regex
It's also possible to do this with just one re...
push_back vs emplace_back
...h_back(Type&& _Val).
But the real C++0x form of emplace_back is really useful: void emplace_back(Args&&...);
Instead of taking a value_type it takes a variadic list of arguments, so that means that you can now perfectly forward the arguments and construct directly an object into a ...
How to access app.config in a blueprint?
...horisation.py which in a package api. I am initializing the blueprint in __init__.py which is used in authorisation.py .
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Best way to show a loading/progress indicator?
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From the Android Developer website: STYLE_SPINNER Creates a ProgressDialog with a circular, spinning progress bar.
– Tequilaman
Dec 26 '14 at 1:15
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Open-sided Android stroke?
... distance of 1px instead of 1dp. This will make the line always visible at all densities. The best solution would be to create dimension resources for each density, to get the best size for each device.
Edit 2
Fun, but I tried to use this 6 years later and I can't get a good result on Lollipop dev...
python pandas dataframe to dictionary
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See the docs for to_dict. You can use it like this:
df.set_index('id').to_dict()
And if you have only one column, to avoid the column name is also a level in the dict (actually, in this case you use the Series.to_dict()):
df.set_index('id')...
Is there an alternative to bastard injection? (AKA poor man's injection via default constructor)
... well-known pattern, but I'll grant that overloaded constructors are marginally more 'in your face' :)
– Mark Seemann
Jul 20 '11 at 7:21
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Replacing all non-alphanumeric characters with empty strings
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Use [^A-Za-z0-9].
Note: removed the space since that is not typically considered alphanumeric.
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What is a word boundary in regex?
... be "identifier" characters (alnums and underscore), not as anything especially useful for English.
– hobbs
Aug 24 '09 at 21:02
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