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How to do this Linq query with group by?

5281
5281 asked
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Last Modified: 2016-02-15
I put two database tables into two generic class lists.  I want to translate the following sql query into  LINQ Query, but I keep getting errors.

SELECT a.ArticleNumber, a.ArticleType, a.AuthorID, b.AuthorID, b.AuthorName
FROM Article AS a INNER JOIN Author as b ON a.AuthorID=b.AuthorID
WHERE a.ArticleNumber=myNumber
GROUP BY a.ArticleNumber, b.AuthorID, b.AuthorName, a.ArticleType

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I tried the following, but there is error for ArticleGroup(), definition of method 'ArticleGroup'  is not accessible in this context.

Dim myNumber as string
Dim ArticleTableList as New List(of clsPaper)     'Class type List holds table Ariticle
Dim AuthorTableList as New List(of clsPeople)  'Class type List holds table Author

Dim CountAritle As clsPaper = (From c In ArticleTableList Join d In AuthorTableList On c.AuthorID Equals d.AuthorID  _
Where c.ArticleNumber = myNumber Group c By c.ArticleNumber, d.AuthorID, d.AuthorName, c.ArticleType _
 Into ArticleGroup() Select c).SingleOrDefault()

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I am using ASP.NET in VB.
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Most Valuable Expert 2011
Top Expert 2015

Commented:
It appears you have a method named ArticleGroup within this code somewhere. That name is in conflict with what you are trying to call your group. Try renaming it in your query.

e.g.

Dim CountAritle As clsPaper = (From c In ArticleTableList Join d In AuthorTableList On c.AuthorID Equals d.AuthorID  _
Where c.ArticleNumber = myNumber Group c By c.ArticleNumber, d.AuthorID, d.AuthorName, c.ArticleType _
 Into theGroup Select c).SingleOrDefault()

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Author

Commented:
I renamed it, it still the same error, .NET compiler automatically add a parentheses behind group name theGroup() in this case.
I think we need rewrite this linq query.  Somewhere is not right.
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Commented:
This one is on us!
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Author

Commented:
Wow.  Excellent.
Fernando SotoRetired
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Distinguished Expert 2017

Commented:
Not a problem 5281, glad I was able to help.

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