大约有 40,000 项符合查询结果（耗时：0.0403秒） [XML]
Linq: GroupBy, Sum and Count
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I don't understand where the first "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)
.Selec...
How do I revert master branch to a tag in git?
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For reference, to revert to the previous commit, you can do a git reset --hard HEAD^
– Geoff
Sep 6 '13 at 2:57
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What makes a SQL statement sargable?
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The most common thing that will make a query non-sargable is to include a field inside a function in the where clause:
SELECT ... FROM ...
WHERE Year(myDate) = 2008
The SQL optimizer can't use an index on myDate, even if one exists...
@UniqueConstraint and @Column(unique = true) in hibernate annotation
...umnNames = {"mask", "group"})}
)
Implies that the values of mask + group combined should be unique. That means you can have, for example, a record with mask.id = 1 and group.id = 1, and if you try to insert another record with mask.id = 1 and group.id = 2, it'll be inserted successfully, whereas i...
How to get CSS to select ID that begins with a string (not in Javascript)?
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61
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jQuery: select an element's class and id at the same time?
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Enable 'xp_cmdshell' SQL Server
...e Permission section of the xp_cmdshell MSDN docs:
http://msdn.microsoft.com/en-us/library/ms190693.aspx:
-- To allow advanced options to be changed.
EXEC sp_configure 'show advanced options', 1
GO
-- To update the currently configured value for advanced options.
RECONFIGURE
GO
-- To enable the f...
Change the mouse cursor on mouse over to anchor-like style
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LINQ Join with Multiple Conditions in On Clause
...SecondProperty = true } equals
new { t2.ProjectID, SecondProperty = t2.Completed } into j1
Based on the comments of @svick, here is another implementation that might make more sense:
from t1 in Projects
from t2 in Tasks.Where(x => t1.ProjectID == x.ProjectID && x.Completed == true)...
What is the difference between Unidirectional and Bidirectional JPA and Hibernate associations?
... elements of Group.users from the database!
So, I can't agree with the recommendation from the Best Practices. You need to design bidirectional relationships carefully, considering use cases (do you need navigational access in both directions?) and possible performance implications.
See also:
D...