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

Select non-persisted values with the VALUES keyword. Then use JOINs to generate lots and lots of combinations (can be extended to create hundreds of thousands of rows and beyond).

SELECT ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n
FROM (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) ones(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) tens(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) hundreds(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) thousands(n)
WHERE ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n BETWEEN @userinput1 AND @userinput2
ORDER BY 1

Demo

A shorter alternative, that is not as easy to understand:

WITH x AS (SELECT n FROM (VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) v(n))
SELECT ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n
FROM x ones,     x tens,      x hundreds,       x thousands
ORDER BY 1

Demo