Question

In SQL, I have a table which have fields a_1,a_2,..., a_10. What kind of query says if I have rows s,t such that s.a_1=t.a_1 ,..., s.a_6=t.a_6 and for some j>6 we have s.a_i<>t.a_i?

Answer 1

Join table to itself on the condition you supplied. Like:

select
   a.ID 
from 
  table as a join table as b 
  on a.a_1 = b.a_1 and ... and a.a_j <> b.a_j