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ORA-00979 not a group by expression
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You must put all columns of the SELECT in the GROUP BY or use functions on them which compress the results to a single value (like MIN, MAX or SUM).
A simple example to understand why this happens: Imagine you have a database like this:
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Concatenating two lists - difference between '+=' and extend()
I've seen there are actually two (maybe more) ways to concatenate lists in Python:
One way is to use the extend() method:
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Is it expensive to use try-catch blocks even if an exception is never thrown?
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try has almost no expense at all. Instead of doing the work of setting up the try at runtime, the code's metadata is structured at compile time such that when an exception is thrown, it now does a relatively expensive operation of walking up the stack an...
How to “properly” create a custom object in JavaScript?
...e result is that in mixed company you will have a mishmash of metaclasses, all behaving slightly differently. What's worse, most JavaScript tutorial material is terrible and serves up some kind of in-between compromise to cover all bases, leaving you very confused. (Probably the author is also confu...
When to wrap quotes around a shell variable?
... quote it if it can either be empty or contain spaces (or any whitespace really) or special characters (wildcards). Not quoting strings with spaces often leads to the shell breaking apart a single argument into many.
$? doesn't need quotes since it's a numeric value. Whether $URL needs it depends o...
mingw-w64 threads: posix vs win32
I'm installing mingw-w64 on Windows and there are two options: win32 threads and posix threads. I know what is the difference between win32 threads and pthreads but I don't understand what is the difference between these two options. I doubt that if I will choose posix threads it will prevent me fro...
What does 'public static void' mean in Java?
...ely different things:
public means that the method is visible and can be called from other objects of other types. Other alternatives are private, protected, package and package-private. See here for more details.
static means that the method is associated with the class, not a specific instance (...
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'
I installed MySQL on Mac OS X Mountain Lion with homebrew install mysql , but when I tried mysql -u root I got the following error:
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How do I install ASP.NET MVC 5 in Visual Studio 2012?
Is there a way to install ASP.NET MVC 5 in Visual Studio 2012?
11 Answers
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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... NULL is less efficient
In PostgreSQL, NOT IN is less efficient
In Oracle, all three methods are the same.
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