Here I am using CTE(Common Table Expression) for Delete duplicate rows.
PARTITION BY : It devides the query result into partitions
Row_NUMBER : gives unique name for all duplicate rows ie., if one row record repeated for 3 times . it gives the index such as 1,2 and 3
Using this query we can delete all duplicate rows in a table
With EmployeeCTE AS
Select *, ROW_NUMBER() Over (Partition BY ID order by ID)as RowIndex
--- Here we are going to delete all duplicate records except one record(original)
Delete from EmployeeCTE Where RowIndex > 1