大约有 40,000 项符合查询结果（耗时：0.0673秒） [XML]
Linq: GroupBy, Sum and Count
...t "result with sample data" is coming from, but the problem in the console app is that you're using SelectMany to look at each item in each group.
I think you just want:
List<ResultLine> result = Lines
.GroupBy(l => l.ProductCode)
.Select(cl => new ResultLine
{
...
Which version of Perl should I use on Windows? [closed]
...
PerlApp does seem like a useful tool (I haven't compared it with Par::Packer), but the PDK it comes in has a $300 price tag.
– Nate Glenn
Dec 19 '13 at 19:48
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Is there a range class in C++11 for use with range based for loops?
...C++ standard library does not have one, but Boost.Range has boost::counting_range, which certainly qualifies. You could also use boost::irange, which is a bit more focused in scope.
C++20's range library will allow you to do this via view::iota(start, end).
...
What is a StoryBoard ID and how can i use this?
... and present it above your current View Controller
And if you are in your app delegate you could use
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard"
bundle: nil];
Edit: Swift
@IBAction func buttonPressed(sen...
Mongoose, Select a specific field with find
...
The _id field is always present unless you explicitly exclude it. Do so using the - syntax:
exports.someValue = function(req, res, next) {
//query with mongoose
var query = dbSchemas.SomeValue.find({}).select('name -_id'...
How does functools partial do what it does?
...g like this (apart from keyword args support etc):
def partial(func, *part_args):
def wrapper(*extra_args):
args = list(part_args)
args.extend(extra_args)
return func(*args)
return wrapper
So, by calling partial(sum2, 4) you create a new function (a callable, to b...
Are HTTPS URLs encrypted?
...ntion a browser). Using a custom https call behind the scenes in a native app. It's a simple solution to making sure your app's sever connection is secure.
– zingle-dingle
May 28 '13 at 23:12
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Break when a value changes using the Visual Studio debugger
...eading somewhere this is a tough feature to implement in debugging managed apps especially with garbage collector involved.
– Gulzar Nazim
Oct 1 '08 at 23:25
27
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How do I install a module globally using npm?
... I installed forever globally (since it is a command line tool) and all my application modules locally.
However, if you want to use some modules globally (i.e. express or mongodb), take this advice (also taken from blog.nodejs.org):
Of course, there are some cases where
you want to do both. C...
Does Django scale? [closed]
I'm building a web application with Django. The reasons I chose Django were:
29 Answers
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