Hi,

I have a Human entity that has an EntitySet property containing Pet entities. I want to select all humans + a string concatenation of their pet's names. For example:

from human in session.Query.All<Human>()
select new {
   Id = human.Id,
   Name = human.Name,
   PetNames = human.Pets.Select(pet => pet.Name)
}

Then I print string.Join(", ", human.PetNames).

Unfortunately, this causes many queries (1 to query all humans, then 1 query to fetch each pet's name). I'd like all of this done in 1 query.

I can't include the string.Join() in the initial projection, because the LINQ translator doesn't support it. Can I write a custom translator for it? Any guidance you can provide?

Thank you!

asked Jan 10 '12 at 22:40

ara's gravatar image

ara
395818791

edited Jan 10 '12 at 22:48


One Answer:

Hello Ara,

I think, this is a nice case to utilize the power of Prefetch feature. For more information and examples see the corresponding section of the manual.

Hope that helps.

answered Jan 11 '12 at 02:05

Dmitri%20Maximov's gravatar image

Dmitri Maximov
22111211

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