giving one union preference

SQL Apprentice Question
Let say I have a query with the following structure:

Select name, mdate, kdate
from table1 a
inner join (
select name, mdate
from table2 b
where a.id = b.id
and mdate >= kdate
union
select name, mdate
from table3 c
where a.id = c.id
and mdate >= kdate
) mindate


When the select mdate from the inner join union (mindate) returns the
same mdate for table b and c, I want to give preference to the c.mdate
and so c.name.


Is there a way to do this?




Celko Answers
>> When the select mdate from the inner join union (mindate) returns the same mdate for table b and c, I want to give preference to the c.mdate and so c.name. <<


This question makes no sense. The poorly named derived table,
Mindate, acts as if it is materialized and you no longer have access
to tables B and C. It is like asking to see the eggs after the cake
has been baked.

Original Source