Question
Considering these things...
class MyClass
{
int ID {get;set;}
string Name {get;set;}
List<MyOtherClass> Things {get;set;}
}
class MyOtherClass
{
int ID {get;set;}
string Value {get;set;}
}
How can I run a LINQ to Entities query that returns a List using a projection like the one below? With an IEnumerable, this works properly (presuming MyClass). Although Things is an IEnumerable, I must use a list.
MyClass myClass = (from MyClassTable mct in this.Context.MyClassTableSet
select new MyClass
{
ID = mct.ID,
Name = mct.Name,
Things = (from MyOtherClass moc in mct.Stuff
where moc.IsActive
select new MyOtherClass
{
ID = moc.ID,
Value = moc.Value
}).AsEnumerable()
}).FirstOrDefault();
Thanks in advance for your assistance!
Accepted Answer
Not you. This portion must be completed in L2O.
Thus, you could:
var q = (from MyClassTable mct in this.Context.MyClassTableSet
select new // note anonymous type; important!
{
ID = mct.ID,
Name = mct.Name,
Things = (from MyOtherClass moc in mct.Stuff
where moc.IsActive
select new MyOtherClass
{
ID = moc.ID,
Value = moc.Value
}
}).AsEnumerable();
MyClass myClass = (from mct in q
select new MyClass
{
ID = mct.ID,
Name = mct.Name,
Things = mct.Things.ToList()
}).FirstOrDefault();
This cannot be accomplished in a single query.
Popular Answer
I'm not sure precisely what you're requesting, butList<T>
does it workIEnumerable<T>
This only serves as an interface for an enumerable sequence.
The ToList() operator, which generates a list instead of an IEnumerable, may be used in code to do your projection and make Things a list instead of an IEnumerable.List<T>
the anyIEnumerable<T>
this:
MyClass myClass = (from MyClassTable mct in this.Context.MyClassTableSet
select new MyClass
{
ID = mct.ID,
Name = mct.Name,
Things = (from MyOtherClass moc in mct.Stuff
where moc.IsActive
select new MyOtherClass
{
ID = moc.ID,
Value = moc.Value
}).ToList()
}).FirstOrDefault();
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