Is there a way to write

orderby newid()

easily with linq? Combined with top 1 this gets a random record from the database.

I tried creating a function mapping, but it seems that Linq to LLBLGen Pro doesn't emit it in the query, unless the function has an argument that e.g. contains one of the fields.

btw, used crappy hack now:

create view [dbo].[randomguid]
as
    select newid() as id
GO



CREATE FUNCTION [dbo].[fn_NewID]
(
    @ID uniqueidentifier
)
RETURNS uniqueidentifier
AS
BEGIN
    return (select id from randomguid)
END


GO

and then map a .NET function to this sql one, including id that is never used.

Not with linq, but here are the workaround in the normal api: http://llblgen.com/TinyForum/Messages.aspx?ThreadID=14725&StartAtMessage=0&#82065 http://llblgen.com/TinyForum/Messages.aspx?ThreadID=1746&StartAtMessage=0&#56874

Already got a workaround with linq. Would be nice though if a functionmapping without arguments or even a default function mapping would be available.

Already got a workaround with linq

Could you please share it.

see SQL script above and then:

                LinqMetaData metaData = new LinqMetaData();

                metaData.CustomFunctionMappings = new FunctionMappingStore();
                metaData.CustomFunctionMappings.Add(new FunctionMapping(typeof(GuidExtensions),"Random",1,"dbo.fn_newID({0})"));

                var result = ( from t in metaData.Tips
                                     orderby GuidExtensions.Random(t.TipId)
                                     select t).FirstOrDefault();

and for guidextensions.cs

public static class GuidExtensions
    {
        public static Guid Random(Guid id)
        {
            throw new NotImplementedException();
        }
    }

try it like this:

metaData.CustomFunctionMappings.Add(new FunctionMapping(typeof(GuidExtensions),"Random",1,"NewID(), {0}"));

and you don't have to create the view and the scalar function