How to "group by" over a range?

Question

hi
I have a table like this:
x     y     AMNT
1     120     12
1     120     93
1     125     31
1     260     15
2     56     16
2     115     49
3     45     71
4     19     11
4     16     48
5     94     52
5     98     47
I want to group records on x , y columns and aggregate on amnt column, in which difference between values of y column be less than 10.
The result is like this:
x     y     sum(AMNT)
1     ?     136
1     260     15
2     56     16
2     115     49
3     45     71
4     ?     59
5     ?     99
What query can I use?

Answer 1

Like this
"afiedt.buf" 25 lines, 901 characters
  1  with t
  2  as
  3  (
  4  select 1 x, 120 y, 12 amt from dual union all
  5  select 1, 120, 93 from dual union all
  6  select 1, 125, 31 from dual union all
  7  select 1, 260, 15 from dual union all
  8  select 2, 56 , 16 from dual union all
  9  select 2, 115, 49 from dual union all
10  select 3, 45 , 71 from dual union all
11  select 4, 19 , 11 from dual union all
12  select 4, 16 , 48 from dual union all
13  select 5, 94 , 52 from dual union all
14  select 5, 98 , 47 from dual
15  )
16  select x, case when max(cnt) = 1 then to_char(min(y)) else '?' end y, sum(amt) amt
17    from (
18            select x, y, amt, y_next, case when y - y_next <= 10 then 1 else 0 end y_ind, count(*) over(partition by x,  case when y - y_next <= 10 then 1 else 0 end) cnt
19              from (
20                      select x, y, amt, nvl(lag(y) over(partition by x order by y), y) y_next
21                        from t
22                   )
23         )
24   group by x, y_ind
25*  order by 1,2 desc
SQL> /
         X Y                                               AMT
         1 ?                                               136
         1 260                                              15
         2 56                                               16
         2 115                                              49
         3 45                                               71
         4 ?                                                59
         5 ?                                                99
7 rows selected.
SQL>