I have an object, Foo
which contains a List<Bar>
.
Bar
contains a List<Baz>
.
Baz
contains a List<Qux>
.
Qux
has a property I want to compare.
If I have List<Foo>
, how do I filter out all Foo
objects from the list where List<Qux>
is empty?
EDIT Updated my question to more appropriately reflect my problem.
If you want to keep a Foo
when there exists some Qux
under it with a certain value, do this:
List<Foo> foos = ...;
IEnumerable<Foo> query = foos
.Where(foo => foo.Bars
.SelectMany(bar => bar.Bazs)
.SelectMany(baz => baz.Quxs)
.Any(qux => qux.SomeProperty == someValue));
If you want to keep a Foo
when all Qux
under it have a certain value, replace Any
with All
.
You can also do this with more clear syntax (like for me in that case)
List<Foo> lst = GetFooList();
var foos = from foo in lst
from bar in foo.Bars
from baz in bar.Bazs
from qux in baz.Quxs
where qux.Property != somevalue
select foo;
Thanks @31eee384 for putting me on the right track.
I also incorporated the Except()
extension to remove the empty lists. I'm sure there is a more efficient method of writing this, so, please post if you know of one.
This is the extension method that I created.
internal static List<Foo> OnlyWithQuxs(this List<Foo> model)
{
var foosToRemove = new List<Foo>();
foreach (var foo in model)
{
var barsToRemove = new List<Bar>();
foreach (var bar in foo.bars)
{
var bazWithQux = new List<Baz>();
var bazsToRemove = new List<Baz>();
foreach (var baz in bar.bazs)
{
baz.Quxs = GetbazQuxs(baz.Id)
.Where(qux => qux.Property == someValue)
.ToList();
bazWithQux.Add(baz);
if (baz.Quxs == null || baz.Quxs.Count() == 0)
bazsToRemove.Add(baz);
}
bar.bazs = bazWithQux.Except(bazsToRemove).ToList();
if (bar.bazs == null || bar.bazs.Count() == 0)
barsToRemove.Add(bar);
}
foo.bars = foo.bars.Except(barsToRemove).ToList();
if (foo.bars == null || foo.bars.Count() == 0)
foosToRemove.Add(foo);
}
return model.Except(foosToRemove).ToList();
}
foos.Where(f=>f.Bars.All(bar=>bar.Bazs.All(baz=>baz.Quxs.Any())>))
This should work where every baz
will not have an empty List<Qux>
var foos = new List<Foo>
{
new Foo {Bars = new List<Bar> {new Bar { Bazs = new List<Baz> { new Baz { Quxs = new List<Qux> { new Qux()} } } } } },
new Foo {Bars = new List<Bar> {new Bar { Bazs = new List<Baz> { new Baz { Quxs = new List<Qux> { new Qux()} } } } } },
new Foo {Bars = new List<Bar> {new Bar { Bazs = new List<Baz> { new Baz { Quxs = new List<Qux> { } } } } } },
};
var r = foos.Where(f => f.Bars.All(bars=>bars.Bazs.All(baz=>baz.Quxs.Any()))).ToList();
class Foo
{
public List<Bar> Bars { get; set; }
}
class Bar
{
public List<Baz> Bazs { get; set; }
}
class Baz
{
public List<Qux> Quxs { get; set; }
}
class Qux { }
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