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Does MySQL ignore null values on unique constraints?
...sult:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
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Do copyright dates need to be updated? [closed]
Every now and then I see a web site that has an old copyright date. In my mind, I always think "Look at the sucker who forgot to update his copyright year!" Then, while I was hard-coding a copyright year into the site I'm currently designing, it suddenly struck me:
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AngularJS $http and $resource
...With $http you're going to be making GET, POST, DELETE type calls manually and processing the objects they return on your own.
$resource wraps $http for use in RESTful web API scenarios.
Speaking VERY generally: A RESTful web service will be a service with one endpoint for a data type that does...
Checking if an Android application is running in the background
... completely reliable:
The right solution (credits go to Dan, CommonsWare and NeTeInStEiN)
Track visibility of your application by yourself using Activity.onPause, Activity.onResume methods. Store "visibility" status in some other class. Good choices are your own implementation of the Application o...
Check whether a path is valid in Python without creating a file at the path's target
I have a path (including directory and file name).
I need to test if the file-name is a valid, e.g. if the file-system will allow me to create a file with such a name.
The file-name has some unicode characters in it.
...
What regex will match every character except comma ',' or semi-colon ';'?
...tion you are using. Most of them have a Split method that takes delimiters and split by them. You might want to use that one with a "normal" (without ^) character class:
[,;]+
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phantomjs not waiting for “full” page load
...or if it takes longer than a second, it will still fail. Such inefficiency and unreliability is unbearable for professional work.
– CodeManX
Jul 15 '15 at 9:35
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What is dynamic programming? [closed]
...be a very long process, but what if I give you the results for n=1,000,000 and n=1,000,001? Suddenly the problem just became more manageable.
Dynamic programming is used a lot in string problems, such as the string edit problem. You solve a subset(s) of the problem and then use that information to ...
How do I parse an ISO 8601-formatted date?
...atetime strings like the one in the question, but also other ISO 8601 date and time strings that don't comply with RFC 3339 (such as ones with no UTC offset, or ones that represent only a date).
>>> import dateutil.parser
>>> dateutil.parser.isoparse('2008-09-03T20:56:35.450686Z'...
Algorithms based on number base systems? [closed]
...erical Representations": essentially, take some representation of a number and convert it into a data structure. To give a flavor, here are the sections of that chapter:
Positional Number Systems
Binary Numbers (Binary Random-Access Lists, Zeroless Representations, Lazy Representations, Segmented ...