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How to use GROUP BY to concatenate strings in MySQL?
...n_group-concat
From the link above, GROUP_CONCAT: This function returns a string result with the concatenated non-NULL values from a group. It returns NULL if there are no non-NULL values.
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Viewing complete strings while debugging in Eclipse
While debugging Java code, Strings in the views "Variables" and "Expressions" show up only till a certain length, after which Eclipse shows "..."
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Cast from VARCHAR to INT - MySQL
...ution. - - - - - - - - - - - - - Long Version: From the manual: To cast a string to a number, you normally need do nothing other than use the string value in numeric context Although I'd use +0 instead of *1 since addition is faster.
– Mindwin
Oct 24 '16 at 14...
boost自定义composite_key_compare比较函数 - C/C++ - 清泛网 - 专注C/C++及内核技术
...DType,&TParam::ID>
>,
composite_key_compare<
//std::less<std::string>
customize_compare
>
>,
ordered_non_unique< tag<TParamValidIndex>,
member<TParam,bool,&TParam::IsValid> >
>
>TParamSet;
typedef boost::multi_index::index<TParamSet,TParamIDIndex>::type TParamSetBy...
CSV file written with Python has blank lines between each row
...ks below), so open outfile with the additional parameter newline='' (empty string) instead.
Examples:
# Python 2
with open('/pythonwork/thefile_subset11.csv', 'wb') as outfile:
writer = csv.writer(outfile)
# Python 3
with open('/pythonwork/thefile_subset11.csv', 'w', newline='') as outfile:
...
PowerShell script to return versions of .NET Framework on a machine?
...le by looking for unique lines that start with ".NET Framework"
Select-String "^.NET" | Select-Object -Unique |
# And flip it so it's key = value
# And convert ".NET FRAMEWORK 4.5.2" to [version]4.5.2
ForEach-Object {
[version]$v, [int]$k = $_ -replace "\.NET Framework " -s...
SQL query to group by day
...er (from Jon Bright):
GROUP BY date(datefield)
For Oracle:
GROUP BY to_char(datefield, 'yyyy-mm-dd')
or faster (from IronGoofy):
GROUP BY trunc(created);
For Informix (by Jonathan Leffler):
GROUP BY date_column
GROUP BY EXTEND(datetime_column, YEAR TO DAY)
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How do I print a double value without scientific notation using Java?
...e format specifier language explained in the documentation.
The default toString() format used in your original code is spelled out here.
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How to avoid “ConcurrentModificationException” while removing elements from `ArrayList` while iterat
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Use an Iterator and call remove():
Iterator<String> iter = myArrayList.iterator();
while (iter.hasNext()) {
String str = iter.next();
if (someCondition)
iter.remove();
}
s...
warning: incompatible implicit declaration of built-in function ‘xyz’
...n-* flags if possible.
Instead of stdlib.h, you should try:
#include <string.h>
That's where strcpy and strncpy are defined, at least according to the strcpy(2) man page.
The exit function is defined in stdlib.h, though, so I don't know what's going on there.
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