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Django: Get an object form the DB, or 'None' if nothing matches
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In Django 1.6 you can use the first() Queryset method. It returns the first object matched by the queryset, or None if there is no matching object.
Usage:
p = Article.objects.order_by('title', 'pub_date').first()
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Which are more performant, CTE or temporary tables?
...to perform multiple processing passes on a set of data.
A CTE can be used either to recurse or to simply improved readability.
And, like a view or inline table valued function can also be treated like a macro to be expanded in the main query
A temp table is another table with some rules around scop...
Common programming mistakes for Clojure developers to avoid [closed]
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Literal Octals
At one point I was reading in a matrix which used leading zeros to maintain proper rows and columns. Mathematically this is correct, since leading zero obviously don't alter the underlying value. Attempts to de...
How do I use reflection to invoke a private method?
...s BindingFlags:
MethodInfo dynMethod = this.GetType().GetMethod("Draw_" + itemType,
BindingFlags.NonPublic | BindingFlags.Instance);
dynMethod.Invoke(this, new object[] { methodParams });
Here's the BindingFlags enumeration documentation.
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How to analyze a java thread dump?
...ead id and NID is: Native thread ID. This ID is highly platform dependent. It's the NID in jstack thread dumps. On Windows, it's simply the OS-level thread ID within a process. On Linux and Solaris, it's the PID of the thread (which in turn is a light-weight process). On Mac OS X, it is said to b...
Best practice multi language website
I've been struggling with this question for quite some months now, but I haven't been in a situation that I needed to explore all possible options before. Right now, I feel like it's time to get to know the possibilities and create my own personal preference to use in my upcoming projects.
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Understanding MongoDB BSON Document size limit
From MongoDB The Definitive Guide:
7 Answers
7
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What is the difference between #import and #include in Objective-C?
...as added to Objective-C as an improved version of #include. Whether or not it's improved, however, is still a matter of debate. #import ensures that a file is only ever included once so that you never have a problem with recursive includes. However, most decent header files protect themselves agains...
java.net.SocketException: Connection reset
...eliberately reset the connection, in a way which I will not document here. It is rare, and generally incorrect, for application software to do this, but it is not unknown for commercial software.
More commonly, it is caused by writing to a connection that the other end has already closed normally. I...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
I have two Python dictionaries, and I want to write a single expression that returns these two dictionaries, merged (i.e. taking the union). The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place.
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