To get the employee details by using PER_PEOPLE_F table

SELECT
PPF.PERSON_ID USERID,
PPF.EMPLOYEE_NUMBER EMPLOYEE_NUM,
PPF.LAST_NAME USER_NAME,
--rtrim(rtrim(EMAIL_ADDRESS,'signodeindia.com'),'@')ALIAS_NAME,
SUBSTR(PPF.EMAIL_ADDRESS,1,INSTR(PPF.EMAIL_ADDRESS,'@',1)-1) ALIAS_NAME,
PPF.EMAIL_ADDRESS,
PPF.LAST_NAME FULL_NAME,
--PPF.EFFECTIVE_START_DATE JOING_DATE,
TO_CHAR(PPF.DATE_OF_BIRTH,'DD-MON-YYYY')DATE_OF_BIRTH,
PAV.DEFAULT_CODE_COMB_ID,
IGCV.SEGMENT2,
IGCV.SEG2_DESC,
IGCV.SEGMENT4 COST_CODE,
IGCV.SEG4_DESC COST_CODE_DESC
,PAV.LOCATION_CODE,
PAV.ADDRESS_LINE_1 ADD1,
PAV.ADDRESS_LINE_2 ADD2,
PAV.ADDRESS_LINE_3 ADD3,
PAV.TOWN_OR_CITY,
PAV.COUNTRY,
PAV.POSTAL_CODE,
PAV.TELEPHONE_NUMBER_1,
PAV.TELEPHONE_NUMBER_2,
PPF.WORK_TELEPHONE TEL
FROM
PER_PEOPLE_F PPF,
PER_ASSIGNMENTS_V7 PAV,
GL_CODE_COMBINATIONS IGCV
WHERE
PPF.PERSON_ID=PAV.PERSON_ID
AND PPF.EMPLOYEE_NUMBER=PAV.ASSIGNMENT_NUMBER
AND PAV.DEFAULT_CODE_COMB_ID=IGCV.CODE_COMBINATION_ID
--AND SUBSTR(PPF.EMAIL_ADDRESS,INSTR(PPF.EMAIL_ADDRESS,'@',1)+1)  != 'ramesh.com'
order by PPF.EMPLOYEE_NUMBER