sql cross join - what use has anyone found for it? [closed]

Answer 1

I've used a CROSS JOIN recently in a report that we use for sales forcasting, the report needs to break out the amount of sales that a sales person has done in each General Ledger account.

So in the report I do something to this effect:

SELECT gla.AccountN, s.SalespersonN
FROM
    GLAccounts gla
    CROSS JOIN Salesperson s
WHERE (gla.SalesAnalysis = 1 OR gla.AccountN = 47500)

This gives me every GL account for every sales person like:

SalesPsn    AccountN
1000    40100
1000    40200
1000    40300
1000    48150
1000    49980
1000    49990
1005    40100
1005    40200
1005    40300
1054    48150
1054    49980
1054    49990
1078    40100
1078    40200
1078    40300
1078    48150
1078    49980
1078    49990
1081    40100
1081    40200
1081    40300
1081    48150
1081    49980
1081    49990
1188    40100
1188    40200
1188    40300
1188    48150
1188    49980
1188    49990

Answer 2

I personally try to avoid cartesian product's in my queries. I suppose have a result set of every combination of your join could be useful, but usually if I end up with one, I know I have something wrong.