>I understand what's being said, and have given another attempt. Does this look better? (I haven't tested it yet):

Are you intending to sum up the bundle field in each datan table? If so this isn't going to do what you want.

If you need the intermediate summations then you can do it in two steps.

SELECT SUM( data1.bundle ) as sumvar FROM lumber!data1 into cursor bundata WHERE siz = szValue and grade = gdValue and length = 2 union all ;
SELECT SUM( data2.bundle ) as sumvar FROM lumber!data2 WHERE siz = szValue and grade = gdValue and length = 2 union all ;
SELECT SUM( data3.bundle ) as sumvar FROM lumber!data3 WHERE siz = szValue and grade = gdValue and length = 2 INTO CURSOR sums

*!* Now you'll see one record with bundle summed for each of the selects
*!* Now take the total

SELECT SUM( sumvar ) FROM sums INTO CURSOR totalsum