OKL Contract NIV Compare

SELECT  OKC.CONTRACT_NUMBER,
        DECODE(OKC.VERSION_NUMBER, 'Current',
           (SELECT meaning from fnd_lookup_values
            WHERE  lookup_type = 'OKL_CONTRACT_VERSION' 
	    AND    language = userenv('LANG')), 
	OKC.VERSION_NUMBER) VERSION_NUMBER,
        OKC.NIV,
	TO_CHAR(OKC.AS_OF_DATE, 'DD-Mon-YYYY') AS_OF_DATE
FROM    OKL_ECC_CV_CONTRACTS_ALL OKC
WHERE OKC.REPORT_ID = :P_REPORT_ID
UNION
SELECT  OKC.CONTRACT_NUMBER,                           
        DECODE(OKC.VERSION_NUMBER2, 'Current',
           (SELECT meaning from fnd_lookup_values
            WHERE  lookup_type = 'OKL_CONTRACT_VERSION' 
	    AND    language = userenv('LANG')), 
	OKC.VERSION_NUMBER2) VERSION_NUMBER,
        OKC.NIV2 NIV,
	TO_CHAR(OKC.AS_OF_DATE2, 'DD-Mon-YYYY') AS_OF_DATE
FROM    OKL_ECC_CV_CONTRACTS_ALL OKC
WHERE OKC.REPORT_ID = :P_REPORT_ID
AND OKC.VERSION_NUMBER2 IS NOT NULL  
ORDER BY 2 DESC