I’m trying to wrap my head around which data structures are the most efficient and when / where to use which ones. Now, it could be that I simply just don’t understand the structures well enough, but how is an ILookup(of key, …) different from a Dictionary(of key, list(of …))? Also where would I want … Read more
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I have a list of orders. I want to select orders based on a set of order statuses. So essentially select orders where order.StatusCode in (“A”, “B”, “C”) // Filter the orders based on the order status var filteredOrders = from order in orders.Order where order.StatusCode.????????(“A”, “B”, “C”) select order; 5 Answers 5
Using the simple example below, what is the best way to return results from multiple tables using Linq to SQL? Say I have two tables: Dogs: Name, Age, BreedId Breeds: BreedId, BreedName I want to return all dogs with their BreedName. I should get all dogs using something like this with no problems: public IQueryable<Dog> … Read more
Using the C# compilers query comprehension features, you can write code like: var names = new string[] { “Dog”, “Cat”, “Giraffe”, “Monkey”, “Tortoise” }; var result = from animalName in names let nameLength = animalName.Length where nameLength > 3 orderby nameLength select animalName; In the query expression above, the let keyword allows a value to … Read more
I got this XML file: <root> <level1 name=”A”> <level2 name=”A1″ /> <level2 name=”A2″ /> </level1> <level1 name=”B”> <level2 name=”B1″ /> <level2 name=”B2″ /> </level1> <level1 name=”C” /> </root> Could someone give me a C# code using LINQ, the simplest way to print this result: (Note the extra space if it is a level2 node) A … Read more
This question already has answers here: Closed 12 years ago. Possible Duplicate: IList<T> to IQueryable<T> I have a List data, but I want a IQueryable data , is it possible from List data to IQueryable data? Show me code 1 Answer 1
I am trying to use LINQ to create a Dictionary<string, List<CustomObject>> from a List<CustomObject>. I can get this to work using “var”, but I don’t want to use anonymous types. Here is what I have var x = (from CustomObject o in ListOfCustomObjects group o by o.PropertyName into t select t.ToList()); I have also tried … Read more
Let’s say I have a class public class MyObject { public int SimpleInt{get;set;} } And I have a List<MyObject>, and I ToList() it and then change one of the SimpleInt, will my change be propagated back to the original list. In other words, what would be the output of the following method? public void RunChangeList() … Read more
I have a property on a class that is an ISet. I’m trying to get the results of a linq query into that property, but can’t figure out how to do so. Basically, looking for the last part of this: ISet<T> foo = new HashedSet<T>(); foo = (from x in bar.Items select x).SOMETHING; Could also … Read more
