title: Delete duplicate records from a SQL table without a primary key
body: <p>I have the below table with the below records in it</p>
  
  <pre><code>create table employee
  (
   EmpId number,
   EmpName varchar2(10),
   EmpSSN varchar2(11)
  );
  
  insert into employee values(1, 'Jack', '555-55-5555');
  insert into employee values (2, 'Joe', '555-56-5555');
  insert into employee values (3, 'Fred', '555-57-5555');
  insert into employee values (4, 'Mike', '555-58-5555');
  insert into employee values (5, 'Cathy', '555-59-5555');
  insert into employee values (6, 'Lisa', '555-70-5555');
  insert into employee values (1, 'Jack', '555-55-5555');
  insert into employee values (4, 'Mike', '555-58-5555');
  insert into employee values (5, 'Cathy', '555-59-5555');
  insert into employee values (6 ,'Lisa', '555-70-5555');
  insert into employee values (5, 'Cathy', '555-59-5555');
  insert into employee values (6, 'Lisa', '555-70-5555');
  </code></pre>
  
  <p>I dont have any primary key in this table .But i have the above records in my table already.
  I want to remove the duplicate records which has the same value in EmpId and EmpSSN fields.</p>
  
  <p>Ex : Emp id 5 </p>
  
  <p>Can any one help me to frame a query to delete those duplicate records</p>
  
  <p>Thanks in advance</p>