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How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...o do an upsert, which is what MySQL calls INSERT ... ON DUPLICATE UPDATE and the standard supports as part of the MERGE operation.
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When to use actors instead of messaging solutions such as WebSphere MQ or Tibco Rendezvous?
I've already read the question and answers to What design decisions would favour Scala's Actors instead of JMS? .
3 Answer...
libxml/tree.h no such file or directory
...rameworks section). On the Mac,
you'll find it at /usr/lib/libxml2.dylib and for the iPhone, you'll
want the
/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.0.sdk/usr/lib/libxml2.dylib
version.
Since libxml2 is a .dylib (not a nice friendly .framework) we still
have on...
Build unsigned APK file with Android Studio
I'm developing an android app with the Android Developer Tool.
Now I tried the new Android Studio, everything works fine if connect my smartphone with the pc and directly run the program in the Android Studio.
But now I want to test the program with other smartphones without connecting them to my pc...
Difference between HEAD and master
What is the difference between the HEAD and master in Git?
3 Answers
3
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undefined reference to boost::system::system_category() when compiling
...do.)
Assuming you use gcc, try adding -lboost_system to your compiler command line in order to link against that library.
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What is the most efficient way of finding all the factors of a number in Python?
...
The reduce(list.__add__, ...) is taking the little lists of [fac1, fac2] and joining them together in one long list.
The [i, n/i] for i in range(1, int(sqrt(n)) + 1) if n % i == 0 returns a pair of factors if the remainder when you divide n by the smaller one is zero (it doesn't need to check the...
Why covariance and contravariance do not support value type
...or not.
You might want to read Eric Lippert's blog post on representation and identity for more on this topic in general.
EDIT: Having reread Eric's blog post myself, it's at least as much about identity as representation, although the two are linked. In particular:
This is why covariant and ...
What does the “__block” keyword mean?
...eated in a special way when it is used inside a block. Normally, variables and their contents that are also used in blocks are copied, thus any modification done to these variables don't show outside the block. When they are marked with __block, the modifications done inside the block are also visib...
Boolean vs boolean in Java
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Yes you can use Boolean/boolean instead.
First one is Object and second one is primitive type.
On first one, you will get more methods which will be useful.
Second one is cheap considering memory expense The second will save you a lot more memory, so go for it
Now choose your way....