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E11000 duplicate key error index in mongodb mongoose
...nt with the sparse index to filter these null values from the unique index and avoid the error.
unique indexes
Sparse indexes only contain entries for documents that have the indexed field, even if the index field contains a null value.
In other words, a sparse index is ok with multiple documents...
Difference between framework vs Library vs IDE vs API vs SDK vs Toolkits? [closed]
...for developing (such as forms designers, resource editors, etc), compiling and debugging applications. e.g Eclipse, Visual Studio.
A Library is a chunk of code that you can call from your own code, to help you do things more quickly/easily. For example, a Bitmap Processing library will provide faci...
Why does git-rebase give me merge conflicts when all I'm doing is squashing commits?
...with over 400 commits, the first couple dozen of which were a lot of trial-and-error. We want to clean up these commits by squashing many down into a single commit. Naturally, git-rebase seems the way to go. My problem is that it ends up with merge conflicts, and these conflicts are not easy to reso...
Integrating MySQL with Python in Windows
...
Download page for python-mysqldb. The page includes binaries for 32 and 64 bit versions of for Python 2.5, 2.6 and 2.7.
There's also discussion on getting rid of the deprecation warning.
UPDATE: This is an old answer. Currently, I would recommend using PyMySQL. It's pure python, so it supp...
Xcode/Simulator: How to run older iOS version?
...s in your binary you will not be able to run it on anything before iOS 4.0 and it will be rejected if you try and submit a binary like this.
You can still run the simulator from 3.2 onwards after upgrading.
In the iPhone Simulator try selecting Hardware -> Version -> 3.2
...
Optional Methods in Java Interface
From my understanding if you implement an interface in java, the methods specified in that interface have to be used by the sub classes implementing the said interface.
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.keyCode vs. .which
... The answer below was written in 2010. Here many years later, both keyCode and which are deprecated in favor of key (for the logical key) and code (for the physical placement of the key). But note that IE doesn't support code, and its support for key is based on an older version of the spec so isn't...
MongoDB and “joins” [duplicate]
...ll only be evaluated when needed. A join (in a SQL database) on the other hand will resolve relationships and return them as if they were a single table (you "join two tables into one").
You can read more about DBRef here:
http://docs.mongodb.org/manual/applications/database-references/
There are ...
How do I initialize a TypeScript object with a JSON object
...hots at this to show a few different ways. They are by no means "complete" and as a disclaimer, I don't think it's a good idea to do it like this. Also the code isn't too clean since I just typed it together rather quickly.
Also as a note: Of course deserializable classes need to have default const...
Plain Old CLR Object vs Data Transfer Object
...POCO follows the rules of OOP. It should (but doesn't have to) have state and behavior. POCO comes from POJO, coined by Martin Fowler [anecdote here]. He used the term POJO as a way to make it more sexy to reject the framework heavy EJB implementations. POCO should be used in the same context in...