SQL & PL/SQL

Hi All,

I have a table and it's having duplicate records.

for one particular employee, he is having multiple records with the same data in the table

EMPNO    ENAME     JOB     SAL     DOB
-------------------------------------------------------
1               A           X        100     1956
2               B           Y        200     1974
1               A           X        100     1956
3               C           Z        300     1920
1               A           X        100     1956
2               B           Y        200     1974
3               C           Z        300     1920
3               C           Z        300     1920
3               C           Z        300     1920
2               B           Y        200     1974
2               B           Y        200     1974
2               B           Y        200     1974
1               A           X        100     1956

like this am having multiple times the duplicates.

I have written the below query to delete the duplicate records. But it is deleting only one record (if we have 5 duplicates it is deleting only 1 ). But I am looking to delete if we have 5 duplicates need to delete 4 duplicates and keep 1 record in the table. Can you please help me out for this.

query which am using to delete the duplicates is 

DELETE FROM Table1 a  
WHERE ROWID IN (SELECT MAX(ROWID)  
                FROM Table2 b 
                WHERE a.ID = b.ID);  

it is deleting only one row but I want to delete 4 records out of 5 and keep one record.

Thanks.