SQL Select 'n' records without a Table

Question

Is there a way of selecting a specific number of rows without creating a table. e.g. if i use the following:

SELECT 1, 2, 3, 4, 5, 6, 7, 8, 9, 10


        

Answer 1

;WITH nums AS
    (SELECT 1 AS value
    UNION ALL
    SELECT value + 1 AS value
    FROM nums
    WHERE nums.value <= 99)
SELECT *
FROM nums  

Answer 2

The Recursive CTE approach - is realy good.

Be just aware of performance difference. Let's play with a million of records:

Recursive CTE approach. Duration = 14 seconds

declare @start int = 1;
declare @end int = 999999;

with numbers as 
(
    select @start as number
    union all
    select number + 1 from numbers where number < @end
)
select * from numbers option(maxrecursion 0);

---

Union All + Cross Join approach. Duration = 6 seconds

with N(n) as 
(
    select 1 union all select 1 union all select 1 union all 
    select 1 union all select 1 union all select 1 union all 
    select 1 union all select 1 union all select 1 union all select 1   
)
select top 999999
    row_number() over(order by (select 1)) as number 
from 
    N n1, N n2, N n3, N n4, N n5, N n6;

---

Table Value Constructor + Cross Join approach. Duration = 6 seconds

(if SQL Server >= 2008)

with N as 
(
    select n from (values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10)) t(n)    
)   
select top 999999
    row_number() over(order by (select 1)) as number
from 
    N n1, N n2, N n3, N n4, N n5, N n6;

---

Recursive CTE + Cross Join approach. :) Duration = 6 seconds

with N(n) as 
(
    select 1 
    union all
    select n + 1 from N where n < 10    
)   
select top 999999
    row_number() over(order by (select 1)) as number 
from 
    N n1, N n2, N n3, N n4, N n5, N n6;

---

We will get more amazing effect if we try to INSERT result into a table variable:

INSERT INTO with Recursive CTE approach. Duration = 17 seconds

declare @R table (Id int primary key clustered);

with numbers as 
(
    select 1 as number
    union all
    select number + 1 from numbers where number < 999999
)
insert into @R 
select * from numbers option(maxrecursion 0);

---

INSERT INTO with Cross Join approach. Duration = 1 second

declare @C table (Id int primary key clustered);

with N as 
(
    select n from (values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10)) t(n)    
) 
insert into @C 
select top 999999
    row_number() over(order by (select 1)) as number
from 
    N n1, N n2, N n3, N n4, N n5, N n6;

---

Here is an interesting article about Tally Tables