framework/resources/Functional/joins/nulleqjoin/neqjnPrtnBy_03.q

SELECT t1.col_vrchr1 c1, t2.col_vrchr1 c2 
FROM l_tblprtnby_chrcl t1, r_tblprtnby_chrcl t2 
WHERE t1.col_vrchr1 = t2.col_vrchr1 OR (t1.col_vrchr1 IS NULL AND t2.col_vrchr1 IS NULL);