Get a random row with LINQtoSQL

Question

Is there a way to return a random row from a table using LINQToSQL?

Answer 1

You can get LinqToSQL to generate SQL which uses the SQL Server NEWID() function. Here is my implementation:

namespace Data    // change to whatever the namespace of your DataContext is, or remove
{
    /// 

    /// Add RANDOM() extension to the Data context...
    /// 
    partial class DefaultDataContext  // change to the name of your DataContext
    {
        [System.Data.Linq.Mapping.Function(Name = "NEWID", IsComposable = true)]
        public Guid Random()
        {
            // this code is not actually executed, it simply provides a way to access 
            // T-SQL "NEWID()" function from Linq to SQL
            throw new NotImplementedException();
        }
    }
}

Example of usage, to pull a random product from the database:

var product = (from p in db.Products     // our DataContext instance is called db here
               orderby db.Random()
               select p).FirstOrDefault()