>>Check this thread Re: Select 3 records Thread #1301530
>>
>>I'm thinking there may be a problem with using ORDER BY clause in 2 different parts of UNION.
>
>Thank you for pointing to the other thread. The TOP requires to have ORDER BY but maybe I only need it in the second SQL Select of the Union. I will try it.

select PK from table inner join (select TOP 50 * from MyTable where PK_VAL > nVar Order by PK_VAL) TopSQL on ... ;
UNION ALL ;
select TOP 50 * from MyTable where PK_VAL < nVar Order by PK_VAL DESC

Would this idea work too?