大约有 40,000 项符合查询结果(耗时:0.0467秒) [XML]
Create a dictionary on a list with grouping
...vert it to a dictionary, as follows:
Dim qry = (From acs In ActualSales _
Group By acs.ProductID Into Group _
Select ProductID, Months = Group.ToDictionary(Function(c) c.Period) _
).ToDictionary(Function(c) c.ProductID)
The resulting query can be used as fo...
Error installing mysql2: Failed to build gem native extension
I am having some problems when trying to install mysql2 gem for Rails. When I try to install it by running bundle install or gem install mysql2 it gives me the following error:
...
Code equivalent to the 'let' keyword in chained LINQ extension method calls
...ime it's executed:
var seq = EnumerableEx.Generate(
new Random(),
_ => true,
_ => _,
x => x.Next());
To see that new random samples show up every time, consider the following
seq.Zip(seq, Tuple.Create).Take(3).Dump();
which produces pairs in which the left and right ar...
AJAX in Chrome sending OPTIONS instead of GET/POST/PUT/DELETE?
...nal web application at work. In IE10 the requests work fine, but in Chrome all the AJAX requests (which there are many) are sent using OPTIONS instead of whatever defined method I give it. Technically my requests are "cross domain." The site is served on localhost:6120 and the service I'm making AJA...
Can't install PIL after Mac OS X 10.9
I've just updated my Mac OS to 10.9 and I discovered that some (all?) of my Python modules are not here anymore, especially the Image one.
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Linq Query keeps throwing “Unable to create a constant value of type System.Object…”, Why?
...tBindingSource.Position =
accountBindingSource.IndexOf(_dataService.Db.Accounts.First(ac => ac.AccountName == name));
accountBindingSource_CurrentChanged(sender, e);
}
buggy code:
private void onTopAccBtnClick(object sender, EventArgs e)
{
accountBin...
How can I correctly prefix a word with “a” and “an”?
...uick filter program that spits out only article text (the download is generally in XML format, along with non-article metadata too).
Find all instances of a(n).... and make an index on the following word and all of its prefixes (you can use a simple suffixtrie for this). This should be case sensitiv...
I want to delete all bin and obj folders to force all projects to rebuild everything
I work with multiple projects, and I want to recursively delete all folders with the name 'bin' or 'obj' that way I am sure that all projects will rebuild everything (sometimes it's the only way to force Visual Studio to forget all about previous builds).
...
Entity Framework: There is already an open DataReader associated with this Command
I am using Entity Framework and occasionally i will get this error.
17 Answers
17
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What does .SD stand for in data.table in R
.SD looks useful but I do not really know what I am doing with it. What does it stand for? Why is there a preceding period (full stop). What is happening when I use it?
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