MAX in LINQ to EF

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MAX in LINQ to EF

Ray K

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Points: 31148
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November 23, 2010 at 1:28 pm

#388293

Does anyone know the LINQ to Entity Framework syntax equivalent of a MAX in SQL (e.g. "select MAX([some INT]) from [some table]")?
I tried to look this up, and, strangely, couldn't find a good answer.
Thanks!
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Jack Corbett SSC Guru Points: 184393 More actions · Answer 1

Does this link answer your question:

http://msdn.microsoft.com/en-us/library/cc716738.aspx

Jack Corbett
Consultant - Straight Path Solutions
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Ray K SSC-Dedicated Points: 31148 More actions · Answer 2

Jack Corbett (11/23/2010)
Does this link answer your question:
http://msdn.microsoft.com/en-us/library/cc716738.aspx

Yes and no. I was hoping there'd be an easy way to do this (something like "(m => max(m.GetID))", for example), but I guess that was wishful thinking on my part. Guess I'll have to mess around with this for a bit.

Thanks for your help, Jack. (Glad to hear you're feeling better, BTW.)

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Jack Corbett SSC Guru Points: 184393 More actions · Answer 3

Wish I could have done better for you. I haven't really looked at EF that much, more Linq to SQL. Aggregation is definitely one of the areas the ORM tools (at least EF and L2S) seem to fall short.

I know I've faced some frustrations with L2S where I could have had it done in an SP and called using ADO.NET in 20 minutes and took a full day to get working with L2S.

Do you have LINQPad[/url]? You should if you are doing Linq or EF.

Jack Corbett
Consultant - Straight Path Solutions
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mister.magoo SSC-Forever Points: 47068 More actions · Answer 4

It's really not that difficult..here is an example of getting a maximum ArticleNumber for each groupName in my articles entity...

var groups = from a in Articles

group a by a.GroupName into g

select new { GroupName = g.Key, _

MaximumArticle = g.Max(a => a.ArticleNumber) };

MM

select geometry::STGeomFromWKB(0x0106000000020000000103000000010000000B0000001000000000000840000000000000003DD8CCCCCCCCCC0840000000000000003DD8CCCCCCCCCC08408014AE47E17AFC3F040000000000104000CDCCCCCCCCEC3F9C999999999913408014AE47E17AFC3F9C99999999991340000000000000003D0000000000001440000000000000003D000000000000144000000000000000400400000000001040000000000000F03F100000000000084000000000000000401000000000000840000000000000003D0103000000010000000B000000000000000000143D000000000000003D009E99999999B93F000000000000003D009E99999999B93F8014AE47E17AFC3F400000000000F03F00CDCCCCCCCCEC3FA06666666666FE3F8014AE47E17AFC3FA06666666666FE3F000000000000003D1800000000000040000000000000003D18000000000000400000000000000040400000000000F03F000000000000F03F000000000000143D0000000000000040000000000000143D000000000000003D, 0);

mister.magoo SSC-Forever Points: 47068 More actions · Answer 5

And here is how to just get the max from an entity

var mm = Articles.Max(w => w.ArticleNumber );

MM

select geometry::STGeomFromWKB(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

Jack Corbett SSC Guru Points: 184393 More actions · Answer 6

mister.magoo (11/23/2010)
It's really not that difficult..here is an example of getting a maximum ArticleNumber for each groupName in my articles entity...
var groups = from a in Articles
group a by a.GroupName into g
select new { GroupName = g.Key, _
MaximumArticle = g.Max(a => a.ArticleNumber) };

Just to play devil's advocate here, but now you are using an anonymous type which partially defeats the purpose of an ORM tool, strong typing.

Also, for a person with a T-SQL background writing:

Select

ColA,

Max(ColB) as maxColB

From

Table

Group By

ColA

in an SP and calling the SP is easier.

Jack Corbett
Consultant - Straight Path Solutions
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mister.magoo SSC-Forever Points: 47068 More actions · Answer 7

Jack Corbett (11/23/2010)
mister.magoo (11/23/2010)
It's really not that difficult..here is an example of getting a maximum ArticleNumber for each groupName in my articles entity...
var groups = from a in Articles
group a by a.GroupName into g
select new { GroupName = g.Key, _
MaximumArticle = g.Max(a => a.ArticleNumber) };
Just to play devil's advocate here, but now you are using an anonymous type which partially defeats the purpose of an ORM tool, strong typing.

Yep. Just showing how it can be done, not saying I do it.(I never have)

Also, for a person with a T-SQL background writing:
Select
ColA,
Max(ColB) as maxColB
From
Table
Group By
ColA
in an SP and calling the SP is easier.

Agreed - but - just being Devil's Advocate's Advocate here - that only applies if the data source behind all the nice strongly typed entities is SQL...;-)

MM

select geometry::STGeomFromWKB(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

Ray K SSC-Dedicated Points: 31148 More actions · Answer 8

mister.magoo (11/23/2010)
And here is how to just get the max from an entity
var mm = Articles.Max(w => w.ArticleNumber );

This looks closer to the syntax I was hoping to find. Let me mess around with this a bit and see what happens.

Thanks for the assist, guys!

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Jack Corbett SSC Guru Points: 184393 More actions · Answer 9

mister.magoo (11/23/2010)
Agreed - but - just being Devil's Advocate's Advocate here - that only applies if the data source behind all the nice strongly typed entities is SQL...;-)

True, but since this is a SQLServerCentral I felt safe in assuming that the backend is some type of RDBMS...:-P

Jack Corbett
Consultant - Straight Path Solutions
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mister.magoo SSC-Forever Points: 47068 More actions · Answer 10

Jack Corbett (11/29/2010)
mister.magoo (11/23/2010)
Agreed - but - just being Devil's Advocate's Advocate here - that only applies if the data source behind all the nice strongly typed entities is SQL...;-)
True, but since this is a SQLServerCentral I felt safe in assuming that the backend is some type of RDBMS...:-P

Fair point! 😛

MM

select geometry::STGeomFromWKB(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