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How do I perform the SQL Join equivalent in MongoDB?
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Of course Mongo is not a relational database, and the devs are being careful to recommend specific use cases for $lookup, but at least as of 3.2 doing join is now possible with MongoDB.
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Sorted collection in Java
...n/should be used for maintaining a sorted list in Java. I have tried Map and Set , but they weren't what I was looking for.
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Override Java System.currentTimeMillis for testing time sensitive code
...commend that instead of messing with the system clock, you bite the bullet and refactor that legacy code to use a replaceable clock. Ideally that should be done with dependency injection, but even if you used a replaceable singleton you would gain testability.
This could almost be automated with se...
append multiple values for one key in a dictionary [duplicate]
I am new to python and I have a list of years and values for each year. What I want to do is check if the year already exists in a dictionary and if it does, append the value to that list of values for the specific key.
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Is it safe to get values from a java.util.HashMap from multiple threads (no modification)?
There is a case where a map will be constructed, and once it is initialized, it will never be modified again. It will however, be accessed (via get(key) only) from multiple threads. Is it safe to use a java.util.HashMap in this way?
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Best practice for Python assert
...l this an example of using them. This is more an example of properties in and of themselves: docs.python.org/library/functions.html#property
– Jason Baker
Jun 3 '09 at 13:43
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Can I Replace Apache with Node.js?
... have a website running on CentOS using the usual suspects (Apache, MySQL, and PHP). Since the time this website was originally launched, it has evolved quite a bit and now I'd like to do fancier things with it—namely real-time notifications. From what I've read, Apache handles this poorly. I'm wo...
HTML table with 100% width, with vertical scroll inside tbody [duplicate]
How can I set for <table> 100% width and put only inside <tbody> vertical scroll for some height?
13 Answer...
What's the use of session.flush() in Hibernate
...) I have class where I am saving object using code id = session.save(obj); and transaction is committed at very next line but obj is not getting saved to DB ,Why? 2) I saved obj using session.save(obj); with commit and while returning I used return obj.getprimaryID(); In this case obj is saved to DB...
Cannot use identity column key generation with ( TABLE_PER_CLASS )
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The problem here is that you mix "table-per-class" inheritance and GenerationType.Auto.
Consider an identity column in MsSQL. It is column based. In a "table-per-class" strategy you use one table per class and each one has an ID.
Try:
@GeneratedValue(strategy = GenerationType.TABLE)
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