Loop through values in rows to find faulty data

Question

Hi all,
We have a column which is supposed to have values in increasing order.(If it doesn't comply with this rule, we want to discard the row). How do I loop through rows for a particular column, in SQL or PL.SQL?
Thanks.

Answer 1

user12295995 wrote:
If it doesn't comply with this rule, we want to discard the rowNot sure what you mean. It looks like you want to get rid of duplicates. If so, use:
DELETE tbl WHERE ROWID NOT IN (SELECTMIN(ROWID) FROM tbl GROUP BY col)
/If you want to identify gaps, use:
with t as (
           select 1 id from dual union all
           select 2 id from dual union all
           select 3 id from dual union all
           select 4 id from dual union all
           select 5 id from dual union all
           select 11 id from dual union all
           select 12 id from dual union all
           select 13 id from dual union all
           select 21 id from dual union all
           select 22 id from dual union all
           select 23 id from dual
select  '[' || (prev_id + 1) || ' - ' || (id - 1) || ']' gap
  from  (
         select  id,
                 lag(id) over(order by id) prev_id
           from  t
  where id > prev_id + 1
  order by id
GAP
[6 - 10]
[14 - 20]
SQL> SY.