>Hi all,
>
>Usually I use the "HAVING" clause in a SELECT statement to limit result rows in a situation where I am doing a GROUP BY at the same time (like a count using a GROUP BY).
>
>Is it legit - i.e. will I get correct results - to use filter conditions in the HAVING clause to avoid repeating a filter condition in a UNION? i.e. I have a 3 way UNION each of which has a couple of unique conditions but then all 3 of them have 3 more conditions. Instead of repeating these last 3 conditions 3 times, I thought maybe I could put them in as a "HAVING" as I think I remember reading that that works like a WHERE clause and is processed after the UNION is done. BTW, the unique conditions are complex enough I don't want to try to code a complicated set of conditions joined by two "OR"s. By doing it as a UNION, it is much more readable.
>
>Just want to confirm. Here is the example:
>
>

>
>SELECT ;
>   File.* ;
>   FROM File ;
>   WHERE <unique conditions> ;
>UNION SELECT ;
>   File.* ;
>   FROM File ;
>   WHERE <more unique conditions> ;
>UNION SELECT ;
>   File.* ;
>   FROM Files ;
>   WHERE <more unique conditions> ;
>HAVING ;
>   < 3 conditions common to the above)
>INTO CURSOR x
>
>

>
>Thanks,
>Albert


You could use UNIONs SELECT as derived table and put WHERE clause there:

SELECT *;
FROM( SELECT  File.* ;
              FROM File ;
      WHERE <unique conditions> ;
      UNION;
      SELECT File.* ;
             FROM File ;
      WHERE <more unique conditions> ;
      UNION;
      SELECT File.* ;
             FROM Files ;
      WHERE <more unique conditions>) Tbl1 ;
WHERE  <3 conditions common to the above>
INTO CURSOR x