ValoresUnicos.sql

SELECT RateChangeDate,
    COUNT(Rate) AS 'Contador',
    COUNT(DISTINCT Rate) AS 'Valores Distintos'
    FROM HumanResources.EmployeePayHistory
    WHERE RateChangeDate >= '2003-01-01T00:00:00.000'
        AND RateChangeDate < '2003-01-10T00:00:00.000'
    GROUP BY RateChangeDate;