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Adding 'serial' to existing column in Postgres
...ERT, SELECT, UPDATE, DELETE) statements in pgSQL AFAIK.
However, setval() does! Thus, the following is absolutely fine:
SELECT setval('foo_a_seq', max(a)) FROM foo;
If there's no data and you don't (want to) know about it, use coalesce() to set the default value:
SELECT setval('foo_a_seq', coalesc...
Is there a better way to express nested namespaces in C++ within the header
..._BEGIN(Foo, Bar, Baz)
class X { };
NAMESPACE_END(Baz, Bar, Foo) // order doesn't matter, NAMESPACE_END(a, b, c) would work equally well
Foo::Bar::Baz::X x;
For nesting deeper than three levels you would have to add helper macros up to the desired count.
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surface plots in matplotlib
...st looks like a square with a slight fold in it. But along which diagonal does the "fold" occur? Is it the "high" diagonal at 0.2 or the "low" diagonal at 0? Both are valid surfaces! So you need to choose a triangulation algorithm before you have a well-defined solution.
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Rename MySQL database [duplicate]
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Does it make sense? Why MySQL developer omitted such a important option?
– Milad Rahimi
Jan 19 '16 at 18:30
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What is the difference between encode/decode?
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The decode method of unicode strings really doesn't have any applications at all (unless you have some non-text data in a unicode string for some reason -- see below). It is mainly there for historical reasons, i think. In Python 3 it is completely gone.
unicode().dec...
Difference between size_t and std::size_t
...ragraph says that it may also define them in top-level namespace and if it does, it must define them identically in std:: and top-level. Most compilers just include the C header and import the names to std::, so the symbols do end up defined in both.
– Jan Hudec
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Image Processing: Algorithm Improvement for 'Coca-Cola Can' Recognition
...if this weren't a linearly-efficient algorithm, or nearly so. It obviously doesn't address your can-bottle discrimination, but at least you'll have your logos.
(Update: for bottle recognition I would look for coke (the brown liquid) adjacent to the logo -- that is, inside the bottle. Or, in the c...
Why doesn't the JVM cache JIT compiled code?
... ...or you could just offer persistence as an option, like Oracle's JVM does -- empower advanced programmers to optimize their application's performance when and where they just know the patterns are not changing, under their responsibility. Why not?!
– Alex Martelli
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Embed git commit hash in a .Net dll
...ash", loads the git hash into an MSBuild property named BuildHash, it only does this if BuildHash is not already defined. This allows you to pass it to MSBuild on the command line, if you prefer. You could pass it to MSBuild like so:
MSBuild.exe myproj.csproj /p:BuildHash=MYHASHVAL
The second target...
How to get the difference between two arrays of objects in JavaScript
... display="Ryan"}
It has one minor advantage over Cerebrus's approach (as does Kasper Moerch's approach) in that it escapes early; if it finds a match, it doesn't bother checking the rest of the list. If I had a curry function handy, I would do this a little differently, but this works fine.
Expl...