In this post, I am sharing a script to copy a unique record from one table to another.

You can perform this activity using ROW_NUMBER() and PARTITION BY clause.

This partition clause identified set of duplicate records and row_number assign an ID for this set.

Below is a full demonstration:

Let’s first create table with some records:

CREATE TABLE dbo.tbl_First
(
 ID INTEGER IDENTITY(1,1)
 ,Name VARCHAR(250)
)
GO
INSERT INTO dbo.tbl_First(Name) VALUES('ABC'),('XYZ'),('ABC'),('EFG'),('PQR'),('EFG'),('RND'),('YFQ'),('XVK'),('ABC')
GO
SELECT *FROM dbo.tbl_First ORDER BY Name 
GO

Result of above select statement is:

You can see ABC and EFG are duplicate name.

Create a second table with copy unique data from the first table:

CREATE TABLE dbo.tbl_Second
(
 ID INTEGER 
 ,Name VARCHAR(250)
)
GO
 
INSERT INTO dbo.tbl_Second
SELECT 
 ID
 ,Name   
FROM
(
 SELECT 
  ID
  ,Name
  ,ROW_NUMBER() OVER (PARTITION BY Name ORDER BY ID) AS RowNumber
 FROM  dbo.tbl_First AS T
)AS T WHERE T.RowNumber = 1 
GO

SELECT *FROM dbo.tbl_Second
GO

The result of above second table is:

Now you can see all names are unique and copied only seven unique records.