LINQ order by null column where order is ascending and nulls should be last

c# linq sorting
sf. picture sf. · Jun 24, 2011 · Viewed 98.9k times · Source

I'm trying to sort a list of products by their price.

The result set needs to list products by price from low to high by the column LowestPrice. However, this column is nullable.

I can sort the list in descending order like so:

var products = from p in _context.Products
   where p.ProductTypeId == 1
   orderby p.LowestPrice.HasValue descending
   orderby p.LowestPrice descending
   select p;

// returns:    102, 101, 100, null, null

However I can't figure out how to sort this in ascending order.

// i'd like: 100, 101, 102, null, null

Answer

DaveShaw picture DaveShaw · Jun 24, 2011

Try putting both columns in the same orderby. 

orderby p.LowestPrice.HasValue descending, p.LowestPrice

Otherwise each orderby is a separate operation on the collection re-ordering it each time.

This should order the ones with a value first, "then" the order of the value.

Related questions

Sort a list alphabetically

I have the following class: class Detail { public Detail() { _details = new List<string>(); } public IList<string> Details { get { return _details; } } private readonly List<string> _details; } Currently I sort the class randomly using the following: …

Read More
How do I sort strings alphabetically while accounting for value when a string is numeric?

I'm trying to sort an array of numbers that are strings and I'd like them to sort numerically. The catch is that I cannot convert the numbers into int. Here is the code: string[] things= new string[] { "105", "101", "102", "103", "90" }; foreach (var thing …

Read More
Use LINQ to move item to top of list

Is there a way to move an item of say id=10 as the first item in a list using LINQ? Item A - id =5 Item B - id = 10 Item C - id =12 Item D - id =1 In this case how …

Read More