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difference between primary key and unique key
...rimary Key is a unique key identifier of the record
Unique Key:
Can be more than one unique key in one table
Unique key can have NULL values
It can be a candidate key
Unique key can be NULL ; multiple rows can have NULL values and therefore may not be considered "unique"
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What's the point of OOP?
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There's no empirical evidence that suggests that object orientation is a more natural way for people to think about the world. There's some work in the field of psychology of programming that shows that OO is not somehow more fitting than other approaches.
Object-oriented representations do not a...
Fatal Error: Allowed Memory Size of 134217728 Bytes Exhausted (CodeIgniter + XML-RPC)
... right 95% of the time. However, there are times when you actually do need more memory. For example, let's say your app is loading a massive amount of data into memory for processing (say a Bill of Material with 15k components). It is not always the case that the code is buggy, sometimes you just ne...
One class per file rule in .NET? [closed]
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More classes in the same file enhances the diff between related classes in only one operation.
– Luca
Mar 12 '10 at 19:02
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What are the differences between django-tastypie and djangorestframework? [closed]
...e docs & codebase of each and trying to get a feel for which suits you more.
Obviously, there's also the 'Why TastyPie?' section in it's README, and the 'REST framework 3'.
See also Daniel Greenfeld's blog post on Choosing an API framework for Django, from May 2012 (Worth noting that this was ...
What's the difference between JPA and Hibernate? [closed]
...ion and Hibernate is a tool for ORM. Also, I understand that Hibernate has more features than JPA 2. But from a practical point of view, what really is the difference?
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Is it bad practice to make a setter return “this”?
...at)
Several overloaded constructors (downside: gets unwieldy once you have more than a few)
Factory/static methods (downside: same as overloaded constructors - gets unwieldy once there is more than a few)
If you're only going to set a few properties at a time I'd say it's not worth returning 'this...
Is returning by rvalue reference more efficient?
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what does the const & qualifier on a member function more than a simple const ?
– galinette
Apr 11 '14 at 11:33
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Are there disadvantages to using a generic varchar(255) for all text-based fields?
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How many Activities vs Fragments?
...y putting the logic into the Fragments, there is no need to write the code more than once; it is available no matter which Activity the Fragment is placed into. This makes it a more powerful pattern than the one suggested by the basic tutorial.
/**
* Helper function to show the details of a...