Oracle, How to filter duplicated row data?

Question

The table has 30+ columns and there are many duplicated row data like this:

col_1  col_2  col_3
1      2      2
2      3      2
1      2      2
3      2      2
1      2      2
2      3      2
3      2      2

I want to select all data and filter these duplicated rows, after filtering, the result is

col_1  col_2  col_3
1      2      2
2      3      2
3      2      2

I found DISTINCT and GROUP BY work but I should type many column names. Are there any easier methods available?

Answer 1

easiest way

select distinct * from table

or

select distinct col_1, col_2, col_3 from table

Answer 2

Adding to @Przemo answer, you better use select distinct * from table,

You can similarly use select unique * from table

Specify DISTINCT or UNIQUE if you want the database to return only one copy of each set of duplicate rows selected.

But not in Group by,

Group by can't be used with *, You must specific column names:

GROUP BY { column-Name [ , column-Name ]*

column-Name must be a column from the current scope of the query