Question

I am looking to design a query in which I need DISTINCT terms in a column without repetition. I am using the SQL Server 2008 R2 edition.

Here is my sample table:

id  bank_code   bank_name   interest_rate
----------------------------------------------------------
1   123         abc         3.5
2   456         xyz         3.7
3   123         abc         3.4
4   789         pqr         3.3
5   123         abc         3.6
6   456         xyz         3.1

What I want is, to sort the table descending on the ‘interest_rates’ column but without any repetition of the terms in ‘bank_code’.

Here is what I want:

id  bank_code   bank_name   interest_rate
----------------------------------------------------------
2   456         xyz         3.7 
5   123         abc         3.6
4   789         pqr         3.3

I have been trying the DISTINCT operator but it selects the unique combination of all the columns and not the single column for repetition.
Here is what I am doing, which clearly would not do get me what I want:

SELECT DISTINCT TOP 5 [ID], [BANK_CODE]
      ,[BANK_NAME]
      ,[INTEREST_RATE]
  FROM [SAMPLE]
  ORDER BY [INTEREST_RATE] DESC

Is there a way to achieve this?
Any help is appreciated.

Answer 1

;WITH x AS 
(
    SELECT id,bank_code,bank_name,interest_rate,
      rn = ROW_NUMBER() OVER (PARTITION BY bank_code ORDER BY interest_rate DESC)
    FROM dbo.[SAMPLE]
)
SELECT id,bank_code,bank_name,interest_rate
FROM x WHERE rn = 1
ORDER BY interest_rate DESC;