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Is there a way to set the fetchmode to eager for more than one object using linq for nhibernate. There seems to be an expand method which only allows me to set one object. However I need to set it for more than one object. Is this possible? Thanks

Chris S
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NabilS
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4 Answers4

106

The new Linq provider does it a little differently:

var customers = session.Query<Customer>().Fetch(c => c.Orders).ToList();

More here: http://mikehadlow.blogspot.com/2010/08/nhibernate-linq-eager-fetching.html

Mike Hadlow
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  • if `Orders` has a sub class of its own, would it load eagerly? if not - how would you change the query to load it? – ilans Dec 15 '16 at 09:22
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    To get grandchilds: `var customers = session.Query() .FetchMany(c => c.Orders) .ThenFetchMany(o => o.OrderLines).ToList();` – ilans Dec 15 '16 at 13:14
19

just use it more then once.

IList<Entity> GetDataFromDatabase()
{
    var query = session.Linq<Entity>();
    query.Expand("Property1");
    query.Expand("Property2");
    return query.ToList();
}
Paco
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8

As far as I can see, this is not equivalent: SetFetchMode hydrates an objects tree and the Expand method retrieves a cartesian product.

Jeff
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1

In contiune to @Mike Hadlow answer, fetching next level (grandchildren) you need to do:

var customers = session.Query<Customer>() .FetchMany(c => c.Orders) .ThenFetchMany(o => o.OrderLines).ToList();

ilans
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