Buscar duplicados usando Clasificación sobre la partición

Question

El siguiente SQL funciona para identificar teléfonos únicos cuando existe una disparidad en LastDate. Pero si los teléfonos duplicados tienen el mismo LastDate exacto, no funciona.

Cualquier idea será apreciada.

SELECT * FROM 
(
    SELECT ID, Phone, [LastDate] 
    ,RANK() OVER (PARTITION BY Phone ORDER BY [LastDate]) AS 'RANK',       
      COUNT(Phone) OVER (PARTITION BY Phone) AS 'MAXCOUNT' 
       FROM MyTable   
       WHERE Groupid = 5 
      ) a 
       WHERE [RANK] = [MAXCOUNT] 

Answer 1

Cambiar el RANK para ROW_NUMBER.

SELECT * 
FROM ( SELECT ID, Phone, [LastDate], 
        ROW_NUMBER() OVER (PARTITION BY Phone ORDER BY [LastDate]) AS 'RANK', 
        COUNT(Phone) OVER (PARTITION BY Phone) AS 'MAXCOUNT' 
      FROM MyTable 
      WHERE Groupid = 5) a 
WHERE [RANK] = [MAXCOUNT]