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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...
The application may be doing too much work on its main thread
I am new to Android SDK/API environment. It's the first I am trying to draw a plot/chart. I tried running different kinds of sample codes the emulator using 3 different free libraries, nothing is showing in the layout screen. The logcat is repeating the following message:
...
How to skip over an element in .map()?
...tion would have kept it.
update — This question gets a lot of attention, and I'd like to add the following clarifying remark. The purpose of .map(), as a concept, is to do exactly what "map" means: transform a list of values into another list of values according to certain rules. Just as a paper m...
How to merge dictionaries of dictionaries?
...for key in b:
if key in a:
if isinstance(a[key], dict) and isinstance(b[key], dict):
merge(a[key], b[key], path + [str(key)])
elif a[key] == b[key]:
pass # same leaf value
else:
raise Exception('Conflict at %...
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?
...
Meaning of $? (dollar question mark) in shell scripts
...
This is the exit status of the last executed command.
For example the command true always returns a status of 0 and false always returns a status of 1:
true
echo $? # echoes 0
false
echo $? # echoes 1
From the manual: (acessible by calling man bash in your shell)
$?...
Importing a Maven project into Eclipse from Git
How can I get the effect of choosing to import from both Maven and Git and have Eclipse properly generate my project?
13 A...
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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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...
Alternatives to gprof [closed]
...used in the presence of mutual recursion. But the visualizer is very nice and light years ahead of gprof.
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