SELECT PERSON_ID EMPLOYEE_ID , FULL_NAME FULL_NAME , EMPLOYEE_NUMBER EMPLOYEE_NUMBER , NATIONAL_IDENTIFIER EMP_SSN , BUSINESS_GROUP_ID BUSINESS_GROUP_ID FROM PER_PEOPLE_F PPF1 WHERE PPF1.EMPLOYEE_NUMBER IS NOT NULL AND PPF1.EFFECTIVE_START_DATE = (SELECT MIN(PPF2.EFFECTIVE_START_DATE) FROM PER_PEOPLE_F PPF2 WHERE PPF2.PERSON_ID = PPF1.PERSON_ID AND PPF2.EMPLOYEE_NUMBER IS NOT NULL AND (SYSDATE BETWEEN PPF2.EFFECTIVE_START_DATE AND PPF2.EFFECTIVE_END_DATE OR PPF2.EFFECTIVE_START_DATE > SYSDATE))