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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...
Record file copy operation with Git
...a file in git using git-mv the status shows that the file has been renamed and even if I alter some portions it still considers to be almost the same thing (which is good because it lets me follow the history of it).
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What's the difference between console.dir and console.log?
...
Now it seems that console.log and console.dir actually return the same representation on [1,2,3] in Firefox.
– xji
Jun 18 '18 at 16:27
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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...
Split a String into an array in Swift?
... that String no longer adopts the SequenceType or CollectionType protocols and you must instead use the .characters property to access a CharacterView type representation of a String instance. (Note: CharacterView does adopt SequenceType and CollectionType protocols).
let fullName = "First Last"
le...
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 ...
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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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...