Question

Goal:
Display the duplicated data, in table testing, that shall be deleted.
However,
If there are two duplicated data that is for instance “3412 New York”. 1 row only should be displayed in the testing table.

Problem:
Don’t know how to do it.
Please keep in mind that this table can be a million of row.

All data from the list

table testing
Region          Category    Energy
----------------------------------
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
3125 New Jersey drink       4
3125 New Jersey drink       4
3125 New Jersey drink       4
3125 New Jersey drink       4
3125 New Jersey drink       4
3412 New York   food        3
3412 New York   food        3
3412 Washington coke        7
3412 california chips       20
3412 california chips       20
3412 california chips       20
3412 california chips       20





Requested result that should display data in table testing
Table testing
Region          Category    Energy
----------------------------------
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
1235 Delaware   candy       5
3125 New Jersey drink       4
3125 New Jersey drink       4
3125 New Jersey drink       4
3125 New Jersey drink       4
3412 New York   food        3
3412 california chips       20
3412 california chips       20
3412 california chips       20

Answer 1

To see the results

SELECT
    Region, Category, Energy
FROM
    (
    SELECT
       Region, Category, Energy,
       ROW_NUMBER() OVER (PARTITION BY Region, Category, Energy ORDER BY Region) AS rn
    FROm
       MyTable
    ) X
WHERE
   X.rn > 1