Article will cover some best practices on how to delete duplicate rows in sql server.

We’ll be using a student table. Query for the table creation

Inserted 4 rows into the table, row with roll Number 1 is repeated twice.

sql server table with duplicate rows - Dotnetmob select * from tbl_Student

following query can be used to check duplicate rows based on rollNumber,

Query result :find duplicate rows in sql server Output shows that rollNumber with ‘1’ is repeated 2 times.



here I will be explaining two methods for deleting duplicate rows.

Method 1 – by keeping original

In this method all duplicate rows will be deleted except the original copy. Check this query

after deletion, student table will be shown as below

delete duplicate rows in sql server but keep original


Method 2 – without keeping original

In this method all repeated rows including original copy will be deleted.


resulting table will be like this


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