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How do I change column default value in PostgreSQL?
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answered Jan 20 '11 at 9:28
Silver LightSilver Light
35.5k2929 gold badges112112 silver badges156156 bronze badges
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Select first occurring element after another element
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207
#many .more.selectors h4 + p { ... }
This is called the adjacent sibling selector.
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Sql Server equivalent of a COUNTIF aggregate function
... a CASE statement, like this:
SELECT SUM(CASE WHEN myColumn=1 THEN 1 ELSE 0 END)
FROM AD_CurrentView
Note: in my own test NULLs were not an issue, though this can be environment dependent. You could handle nulls such as:
SELECT SUM(CASE WHEN ISNULL(myColumn,0)=1 THEN 1 ELSE 0 END)
FROM AD_Curren...
Mapping composite keys using EF code first
...ld need to do in your code:
public class MyTable
{
[Key, Column(Order = 0)]
public string SomeId { get; set; }
[Key, Column(Order = 1)]
public int OtherId { get; set; }
}
You can also look at this SO question. If you want official documentation, I would recommend looking at the official ...
ipython: print complete history (not just current session)
....history.HistoryAccessor(profile='default')
profile_hist.get_session_info(100)
This will print out something like
(100, datetime.datetime(2018, 2, 13, 19, 8, 30, 40691), None, None, '')
This means that the session 100 started on the 13th of Feb 2018 19:08:30.
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Does async(launch::async) in C++11 make thread pools obsolete for avoiding expensive thread creation
...verhead for creating a thread to handle a function call is something like 10000 or more times slower than a plain function call. So, if you're issuing a lot of small function calls, a thread pool might be a good idea.
It's quite apparent that the standard C++ library that ships with g++ doesn't hav...
Pass variables to Ruby script via command line
...uts "Argument: #{a}"
end
then
$ ./test.rb "test1 test2"
or
v1 = ARGV[0]
v2 = ARGV[1]
puts v1 #prints test1
puts v2 #prints test2
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Getting exact error type in from DbValidationException
...iest way I've found to get instant insight into these errors.
For Visual 2012+ users who care only about the first error and might not have a catch block, you can even do:
((System.Data.Entity.Validation.DbEntityValidationException)$exception).EntityValidationErrors.First().ValidationErrors.First(...
How exactly does tail recursion work?
...mply able to transform this
int fac_times (int n, int acc) {
if (n == 0) return acc;
else return fac_times(n - 1, acc * n);
}
into something like this:
int fac_times (int n, int acc) {
label:
if (n == 0) return acc;
acc *= n--;
goto label;
}
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relative path in require_once doesn't work
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answered Mar 20 '11 at 22:09
RaisenRaisen
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