Bob Hall
rjhjr at cox.net
Wed Jan 12 09:39:48 CST 2005
On Wed, Jan 12, 2005 at 01:51:38PM +0100, Pedro Janssen wrote: > Hello group, > > for a statistic analyses of DNA-samples i need to compare each sample from a group with eachother sample from another group. I have 7 groups with up to 17 samples. Let me explain what i need in an example. > > I have > > Two tables group1 and group2, with each two records. > > > i need the average of: > group1_record1 + group2_record1 > group1_record2 + group2_record1 > group1_record1 + group2_record2 > group1_record2 + group2_record2 > > > and this for 7 groups up to 17 records > > > Is this possible in a query per 2 groups, > or can this been done in total by code? Pedro, your example is a little ambiguous. Assuming that you want to add records and take the average, and not add columns and take the average, the query is a simple Cartesian product. Assuming a column in group1 named First and a column in group2 named Second: SELECT Avg(group1.First + group2.Second) AS Mean >From group1, group2; If you had tables with thousands of records, this would take forever to run. But as long as you've got less than 100 records in each table, it should be OK. I apologize if I misunderstand what you're trying to do. Bob Hall