Find all column comments : all_col_comments « System Tables Data Dictionary « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. System Tables Data Dictionary
3. all_col_comments

SQL>
SQL> SELECT     column_name, comments
  2  FROM       all_col_comments
  3  WHERE      table_name = UPPER('&&table_name');
old   3: WHERE      table_name = UPPER('&&table_name')
new   3: WHERE      table_name = UPPER('')

no rows selected

SQL> UNDEFINE table_name
SQL>