Question

I have a query:

select * from (select top 100 percent ... from [table] 
    where [field1] is not null
    order by [field1]) a 
union all 
select * from (select top 100 percent ... from [table]
    where [field1] is null 
    order by [field2]) b

The subqueries are ordering their results correctly. I want the exact results of the first subquery, THEN the exact results of the second subquery. However, I’m actually getting the concatenated results ordered in some odd way that I can’t even discern a pattern from. I have [field2] values scattered about the result set apparently at random.

How can I get the first query results on top, and the second query results on bottom?

Edit: To clarify, I want the top query ordered by its own conditions, and then I want the bottom query ordered by its own conditions.

Answer 1

I am not sure, whether or not UNION ALL is meant to preserve the order of rows.
You can force the order you want by using the following statement:

select [field1] from
(
    select * from
    (select 1 as query_number, [field1], [field1] as [order_field] from [table] 
        where [field1] is not null) a 
    union all 
    select * from
    (select 2 as query_number, [field1], [field2] as [order_field] from [table]
        where [field1] is null) b
)
order by query_number, [order_field];