Linq to Sql GroupJoin Paging oddity

Posted by OllyA on Stack Overflow See other posts from Stack Overflow or by OllyA
Published on 2010-05-12T08:29:33Z Indexed on 2010/05/12 8:34 UTC
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Filed under:

c#

|

linq-to-sql

|

grouping

|

pagination

I have noticed a strange Sql Translation in a LinqToSql Query I was trying to optimise.

If I execute the following

Recipients.GroupJoin(
        RecipientAttributes, 
        x => x.Recipient_Id, 
        y => y.Recipient_Id, 
        (x,y) => new {Recipient = x, Attributes = y})
    .Skip(1)
    .Take(1000)

It executes in a single query as expected.

However

Recipients.GroupJoin(
        RecipientAttributes, 
        x => x.Recipient_Id, 
        y => y.Recipient_Id, 
        (x,y) => new {Recipient = x, Attributes = y})
    .Skip(0)
    .Take(1000)

executes in a separate query for each Attributes selection.

Removing the Skip(0) makes no difference either.

Can anyone explain this and is there something I can do to get the first page query executing in a single sql statement?

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