How delete duplicate date from SQL Server

Hi all

Sometime we found duplicate data in our database. we stuck how to remove it from database.find it and manually delete it by key or create program for delete it from code side.so need get data and loop it and check is duplicate and delete it.this is make very lengthy process , I have one solution in SQL side.but it tricky and use carefully.

First I need one table like user and have some columns like id,email and name.

 

Here in this table we can see some emails are duplicate like abc@gmail.com.

We create one SQL query for this table.

 

From this SQL Query i get this result.

 Here we found row_num new column, this display number of duplicate data,how much time email come in repeat. 

Now we need to delete this duplicate data. execute new query for delete same like just add delete action in query.

DELETE FROM temp WHERE row_num > 1;

After this quary execute delete all duplicate email data from table. 

Test it and use it.Enjoy coding