HackerRank Print Prime Numbers problem solution

In this HackerRank Print Prime Numbers problem solution Write a query to print all prime numbers less than or equal to 1000. Print your result on a single line, and use the ampersand (&) character as your separator (instead of a space).

For example, the output for all prime numbers <= 10 would be:

2&3&5&7

Problem solution MS SQL.

declare @result1 nvarchar(4000) = '2'

declare @n int = 1000

declare @i decimal(10,5) = 3

declare @boundary int
declare @isPrime int
declare @loop int

while @i < @n
begin
    select @boundary = cast(Sqrt(@i) as int)
    set @loop = 3
    set @isprime = 1

    if @i = 1 begin set @isprime = 0 end
    if @i = 2 begin set @isprime = 1 end
    if @i % 2 = 0 begin set @isprime = 0 end

    while @loop <= @boundary and @isprime = 1
    begin
        if @i % @loop = 0 begin set @isprime = 0 end
        set @loop = @loop + 2
    end

    if @isprime = 1
    begin
        set @result1 = @result1 + '&' + cast(cast(@i as int) as nvarchar(10))
    end

    set @i = @i + 1
end

select @result1

Problem solution in Oracle.

select listagg (l, '&') 
WITHIN GROUP 
(ORDER BY l) enames
from (   
select  1 as x,l
    from (select level l from dual connect by level <= 1000)
       , (select level m from dual connect by level <= 1000)
   where m<=l
   group by l
  having count(case l/m when trunc(l/m) then 'Y' end) = 2
   order by l)
group by x;

Problem solution in DB2.

with dummy(id) as (
    select 2 from SYSIBM.SYSDUMMY1    
    union all
    select id + 1 from dummy where id < 1000
)

select '2&'||PN from (
select LISTAGG(PN,'&')PN from (
select PN from (select a.id PN, b.id FN, case when MOD(a.id, b.id) = 0 then 'N' else 'Y' end MS from dummy a inner join dummy b
on 1=1 and a.id > b.id
 order by a.id, b.id)
 group by PN
 having LISTAGG(MS,'') not like '%N%'
)
)    
;