How to generate a range of numbers between two numbers?

Question

I have two numbers as input from the user, like for example 1000 and 1050.

How do I generate the numbers between these two numbers, using

Answer 1

If you don't have a problem installing a CLR assembly in your server a good option is writing a table valued function in .NET. That way you can use a simple syntax, making it easy to join with other queries and as a bonus won't waste memory because the result is streamed.

Create a project containing the following class:

using System;
using System.Collections;
using System.Data;
using System.Data.Sql;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;

namespace YourNamespace
{
   public sealed class SequenceGenerator
    {
        [SqlFunction(FillRowMethodName = "FillRow")]
        public static IEnumerable Generate(SqlInt32 start, SqlInt32 end)
        {
            int _start = start.Value;
            int _end = end.Value;
            for (int i = _start; i <= _end; i++)
                yield return i;
        }

        public static void FillRow(Object obj, out int i)
        {
            i = (int)obj;
        }

        private SequenceGenerator() { }
    }
}

Put the assembly somewhere on the server and run:

USE db;
CREATE ASSEMBLY SqlUtil FROM 'c:\path\to\assembly.dll'
WITH permission_set=Safe;

CREATE FUNCTION [Seq](@start int, @end int) 
RETURNS TABLE(i int)
AS EXTERNAL NAME [SqlUtil].[YourNamespace.SequenceGenerator].[Generate];

Now you can run:

select * from dbo.seq(1, 1000000)