How to remove duplicates from table using SQL query

Question

I have a table which is as follows:

emp_name   emp_address  sex  matial_status  
uuuu       eee          m    s
iiii       iii          f    s
uuuu       eee         


        

Answer 1

The best answer is here:
Use this SQL statement to identify the extra duplicated rows:

 select * from Employee a 

    where %%physloc%% > 

        (select min(%%physloc%%) from Employee b 

            where a.emp_name=b.emp_name and a.emp_address=b.emp_address and a.sex=b.sex); 

you will get the extra row:

uuuu   eee m   s 

Use this SQL statement to delete the extra duplicated rows:

 delete from Employee a 

    where %%physloc%% > 

        (select min(%%physloc%%) from Employee b 

            where a.emp_name=b.emp_name and a.emp_address=b.emp_address and a.sex=b.sex); 
 

For all duplicated records, only the one with lowest physical location is kept. This method can be applied to remove all kinds of duplicated rows.

I am assuming that you use MS SQL Server. If you are using Oracle DB, then you can just replace '%%physloc%%' with 'rowid'

Enjoy the code!