Sum() function

Hi, Here is a query I need to create. This query is run frm Excel (thru MS Query) conencted with ODBC drivers to an Informix Database stored on Unix. The quey posted here works rather well though I got a little problem in the output result. Since"inv2.in2_qte_en_main " is a quantity field which has up to 5 rows "inv2.in2" table, the output will show all records that contain 0. BUT... There is rows that have another digit than 0 which means that the real total is not 0 but all the sum of all rows of that table. So basically, I need to sum "inv2.in2_qte_en_main " up dans compare it to 0. If it 0 than is't OK but I can't get the SUM() function to work please take a look at the query below to see how can I get this to work. Notice the {fn LENGTH... part which is required in Excel (MS Query) query to run. I thought that it would be the case with SUM() but I have a "expression mixes columns with aggregates" when I use it. I did the following: {SUM(inv2.in2_qte_en_main)} =0 SELECT inv1.in1_code, inv1.in1_desc_f,inv2.in2_qte_en_main FROM prog.inv1 inv1, prog.inv2 inv2 WHERE inv2.in2_in1_code = inv1.in1_code AND {fn LENGTH(inv1.in1_code)} <=6 AND inv2.in2_qte_en_main =0 AND inv1.in1_fo1_code_grp='1' ORDER BY inv1.in1_code Thanks in advance. Steve Amirault