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Check if a row exists, otherwise insert

... things can overbook a flight, as it will insert a new row when there are 10 tickets max and you are booking 20. share | improve this answer | follow | ...
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static function in C

...t); /* prototype */ int f2(int); /* prototype */ int main(void) { f1(10); /* ok, f1 is visible to the linker */ f2(12); /* nope, f2 is not visible to the linker */ return 0; } share | ...
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Google Maps v3 - limit viewable area and zoom level

...script> </head> <body> <div id="map" style="width: 400px; height: 300px;"></div> <script type="text/javascript"> // This is the minimum zoom level that we'll allow var minZoomLevel = 5; var map = new google.maps.Map(document.getElementById('map'...
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CMake not able to find OpenSSL library

... I had the same problem (openssl) and this worked for me on Ubuntu 14.04.1 LTS. The solution is the same up to Ubuntu 18.04 (tested). sudo apt-get install libssl-dev share | improve this answ...
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Sequelize Unknown column '*.createdAt' in 'field list'

...sequelize = new Sequelize('sequelize_test', 'root', null, { host: "127.0.0.1", dialect: 'mysql', define: { timestamps: false } }); share | improve this answer | ...
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JavaScript for…in vs for

...which idiom is best understood. An array is iterated using: for (var i = 0; i < a.length; i++) //do stuff with a[i] An object being used as an associative array is iterated using: for (var key in o) //do stuff with o[key] Unless you have earth shattering reasons, stick to the establis...
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What exactly is a reentrant function?

...t, everything seems ok… But wait: int main() { foo(bar); return 0; } If the lock on mutex is not recursive, then here's what will happen, in the main thread: main will call foo. foo will acquire the lock. foo will call bar, which will call foo. the 2nd foo will try to acquire the lock...
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Chaining multiple MapReduce jobs in Hadoop

... answered Mar 24 '10 at 22:31 Binary NerdBinary Nerd 13.1k44 gold badges3737 silver badges4141 bronze badges ...
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Saving and Reading Bitmaps/Images from Internal memory in Android

... OutputStream bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos); } catch (Exception e) { e.printStackTrace(); } finally { try { fos.close(); } catch (IOException e) { e.printStackTrace(); ...
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Why do we need a pure virtual destructor in C++?

...unctions can have implementations). struct foo { virtual void bar() = 0; }; void foo::bar() { /* default implementation */ } class foof : public foo { void bar() { foo::bar(); } // have to explicitly call default implementation. }; ...