Specifying a Parameter Default Value

gistfile1.txt

CREATE PROCEDURE [dbo].[spGetAutomobiles]  
    @Id int = 0,
    @Make nvarchar(100) = ''
AS  
BEGIN  
    SELECT * 
    FROM Automobiles a with (nolock)
    WHERE (@Id = 0 OR a.Id = @Id)
    AND (@Make = '' OR a.Make = @Make)
END

//Invoke from F#
let getById id = async {  
    use sproc = new Db.dbo.spGetAutomobiles()
    return! sproc.AsyncExecuteSingle(id)
    }

let getByMake make = async {  
    use sproc = new Db.dbo.spGetAutomobiles()
    return! sproc.AsyncExecute(Make = make)
    }