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Object-orientation in C
...It tries to keep minimal the available concepts for the sake of simplicity and flexibility: uniform object oriented programming including open classes, metaclasses, property metaclasses, generics, multimethods, delegation, ownership, exceptions, contracts and closures. There is a draft paper (PDF) ...
SQL - using alias in Group By
...d because they must have been introduced in a previous step.
So in Oracle and SQL Server, you cannot use a term in the GROUP BY clause that you define in the SELECT clause because the GROUP BY is executed before the SELECT clause.
There are exceptions though: MySQL and Postgres seem to have additi...
FB OpenGraph og:image not pulling images (possibly https?)
...icate issue. I've searched for same or similar problems on SO extensively, and due to the nature of troubleshooting before asking, I believe this problem is unique.
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Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...re allowed (e.g. changing order of elements of each vector, changing order and names of variables, shortening variables, changing case of strings). From this, you should be able to figure out what was missing from one or the other. For example (this is not very elegant):
difference <-
data.fr...
How to export a Vagrant virtual machine to transfer it
I have a vagrant box up and running (configured with a LAMP stack). I need to transfer it to another PC. How can I export it?
I guess that I can get a file (or files) that can be copied to another PC, so there I can run some command to import the vagrant box.
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Unable to copy file - access to the path is denied
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I solved this problem by deleting the contentious files from bin folder and rebuilding the project.
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python assert with and without parenthesis
...through a full interpreter, not through IDLE. Because assert is a keyword and not a function, you are actually passing in a tuple as the first argument and leaving off the second argument.
Recall that non-empty tuples evaluate to True, and since the assertion message is optional, you've essentiall...
How do I find duplicate values in a table in Oracle?
...est SQL statement that will return the duplicate values for a given column and the count of their occurrences in an Oracle database table?
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Check whether number is even or odd
...r is even or odd? I've been wanting to figure this out for a long time now and haven't gotten anywhere.
16 Answers
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snprintf and Visual Studio 2010
I'm unfortunate enough to be stuck using VS 2010 for a project, and noticed the following code still doesn't build using the non-standards compliant compiler:
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