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Can we use join for two different database tables?
...t both databases must be accessible in the same security context. In other words, if you log in with different credentials for the two databases then the above won't work. In that case you would probably have to use "Linked Servers".
– Ian Goldby
Jan 6 '16 at 1...
Throw an error in a MySQL trigger
...--if NEW update value of the attribute age = 1 and OLD value was 0
--key word OLD and NEW let you distinguish between the old and new value of an attribute
IF (NEW.state = 1 AND OLD.state = 0) THEN
signal sqlstate '-20000' set message_text = 'hey it's an error!';
END IF;
END @@...
Check if a folder exist in a directory and create them using C#
...@"C:\a\b\c\d") suffices, even if C:\a does not exist yet.)
Let me add a word of caution about your choice of directory, though: Creating a folder directly below the system partition root C:\ is frowned upon. Consider letting the user choose a folder or creating a folder in %APPDATA% or %LOCALAPPD...
Remove autolayout (constraints) in Interface Builder
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A picture tells more than 1000 words!
– Klaas
Mar 9 '14 at 22:39
Yes, the ...
Java generics - why is “extends T” allowed but not “implements T”?
...type parameter, list the type parameter's name, followed by the extends keyword, followed by its upper bound […]. Note that, in this context, extends is used in a general sense to mean either extends (as in classes) or implements (as in interfaces).
So there you have it, it's a bit confusing, an...
How can I pass a parameter to a Java Thread?
...new MyThread instance using the desired argument for each Thread. In other words, to get a thread up and running we need to create two objects: Thread and MyThread. Is this considered bad, performance-wise?
– Isaac Kleinman
Oct 15 '13 at 21:19
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DTO = ViewModel?
... as parameters for controller methods (or actions) in the WebApi. In other words, JSON is posted to those methods and with some MVC magic, the data is automatically converted to DTOs before being passed to the methods. Do you think it is wrong to use DTOs in this case. Should ViewModels be used with...
Constructor in an Interface?
...o call both interface constructors when constructing an instance. In other words: In my example, the instance has both a name and a list, so each instance needs to instantiate both the name and the list.
– daniel kullmann
Apr 8 '19 at 15:59
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How can I unstage my files again after making a local commit?
... reset --soft didn't work, but git reset HEAD^ did
– wordsforthewise
Oct 4 '16 at 19:21
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Difference between static class and singleton pattern?
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@Goran I was initially very confused by your wording. You said "you cannot call static methods on an instance". I read that as "if you have a reference to an instantiated object, you cannot call any static methods it may have." That is of course, incorrect. After readin...