cartesian product without repeating pairs inversed

elaich · #1 (**permalink**) 12-21-10, 21:36

i have a table with one column, i want to extract all pairs (a,b) where a in table and b in table and if (a,b) is on the result (b,a) must not be extracted ..
can i do that white an sql request ?

r937 · #2 (**permalink**) 12-22-10, 00:43

Code:

SELECT t1.col AS a, t2.col AS b
  FROM daTable AS t1
CROSS
  JOIN daTable AS t2
 WHERE t1.col < t2.col

of course, this only works if the col values are unique, which they would have to be because the table has only one column, so this column has to be the primary key, and therefore unique

otherwise it's not a table, it's a bag

elaich · #3 (**permalink**) 12-22-10, 16:34

Yes, This is it !! Thanks

Internet Services

Web Development

Digital Marketing

Consumer Tech