Question

‘test_table’ contains a column called vendor, with char values from 1 to 9, 1 being highest priority. ‘test_table’ also has another column named match, with char values either ‘I’ or ‘H’, with ‘I’ receiving higher priority. I want to return all rows with unique values in ID, prioritized by match, then vendor.

Test_Table

ID  Vendor  Match  
 1    3      I  
 1    2      I  
 1    4      H  
 2    1      H  
 2    1      I  
 3    1      H  
 3    2      I  

Results Desired

ID  Vendor  Match   
1     2   I  
2     1   I   
3     2   I  


SELECT *
FROM 
    (SELECT ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID) AS RowNo, * 
     FROM test_table) x
WHERE RowNo = 1 
ORDER BY ID

Any help would be greatly appreciated. Thank you!

Answer 1

You need to have an order by clause for match column ( character comparison happens based on ascii value) and another one on vendor column . You can even remove ascii keyowrd ( for the sake of clarity i have written) and simply use the column name in order by clause

Try this :

 ;With cte as 
  ( 
  Select ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ascii(match) desc ,vendor )
   AS RowNo,  Id,Vendor ,Match 
  FROM test_table
  )
  Select Id,Vendor,Match from cte
  WHERE RowNo = 1