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SQLite UPSERT / UPDATE OR INSERT
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For now, no this release in Ubuntu repository yet.
– bl79
Jun 9 '18 at 20:21
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When to use virtual destructors?
...Here, you'll notice that I didn't declare Base's destructor to be virtual. Now, let's have a look at the following snippet:
Base *b = new Derived();
// use b
delete b; // Here's the problem!
Since Base's destructor is not virtual and b is a Base* pointing to a Derived object, delete b has undefin...
Facebook Android Generate Key Hash
...ate a new certificate when you next try to build a debug package.
Let me know if that works.
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How to change the commit author for one specific commit?
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If you don't know what editor you're in, the answer is likely vim. To save and quit, type Esc : w q Enter. On the other hand, if it's Nano and you see things like "WriteOut: ^O" along the bottom, then you should use Ctrl+O, Enter, Ctrl+X i...
Using global variables in a function
...bal variables are so dangerous, Python wants to make sure that you really know that's what you're playing with by explicitly requiring the global keyword.
See other answers if you want to share a global variable across modules.
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Disabling Chrome cache for website development
...iller that clears the cache on every page load.
Chrome Store Link (free)
(Now without malware!)
Now my mock json, javascript, css, html and data refreshes every time on every page load.
I never have to worry if I need to clear my cache.
There are about 20 cache cleaners for Chrome I found, but ...
Best way to merge two maps and sum the values of same key?
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The shortest answer I know of that uses only the standard library is
map1 ++ map2.map{ case (k,v) => k -> (v + map1.getOrElse(k,0)) }
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Differences between fork and exec
...d process (parent) as its parent PID (PPID). Because the two processes are now running exactly the same code, they can tell which is which by the return code of fork - the child gets 0, the parent gets the PID of the child. This is all, of course, assuming the fork call works - if not, no child is c...
When do we have to use copy constructors?
I know that C++ compiler creates a copy constructor for a class. In which case do we have to write a user-defined copy constructor? Can you give some examples?
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How to thoroughly purge and reinstall postgresql on ubuntu? [closed]
...ake sure PostgreSQL isn't running. ps -C postgres should show no results.
Now run:
apt-get --purge remove postgresql\*
to remove everything PostgreSQL from your system. Just purging the postgres package isn't enough since it's just an empty meta-package.
Once all PostgreSQL packages have been r...