Finding duplicate ranges for rows in a table

Question

Data in the table
ROW NUM ID A_FROM A_TO B_FROM B_TO
1 1 1 10 1 10
2 1 1 20 2 20
3 1 3 30 2 20
4 2 10 20 10 20
5 2 10 30 20 30
6 3 10 20 10 20
I want to identify rows based on "ID" columns which has overlaping range of data for column A and column B.
example
In above data based on ID 1 the row # 2 should be flagged due to the fact that col A_FROM and A_TO in row1 overlaps with row #1.
Also, row #3 should be flagged due to the fact that col B_FROM and B_TO in row2 overlapps with row #2.
Any help is appreciated.

Answer 1

TABLE - "rate_table"
ID     A_FROM     A_TO     B_FROM     B_TO     RATE
1     10     20     100     200     0.5
1     10     30     201     300     0.25
1     31     40     200     300     0.25
2     10     20     1000     2000     0.275
2     21     30     1000     2000     0.385
3     10     20     1000     2000     0.658
3     10     30     2000     5000     0.541
3     31     40     1000     2000     0.695
Above table is being used to update another table based on ID column
Update Statement
Update table1 t
set t.rate = (select r.rate from rate_table r
where t.id = r.id and
(t.col_a between r.a_from and r.a_to) and
(t.col_b between r.b_from and r.b_to) )
where exists
(select 0 from rate_table r
where t.id = r.id and
(t.col_a between r.a_from and r.a_to) and
(t.col_b between r.b_from and r.b_to) )
This update would return error
"ORA-01427: single-row subquery returns more than one row"
This is due to the fact that while matching records against table TABLE1 to RATE_TABLE, the range for specific ID are overlapping.
My question.
How can I identity or avoid ORA-01427 error on the update statement? or how do i identity overlapping range records in RATE_TABLE?