SELECT
    MIN(CASE WHEN occupation = 'Doctor' THEN name END) AS Doctor,
    MIN(CASE WHEN occupation = 'Professor' THEN name END) AS Professor,
    MIN(CASE WHEN occupation = 'Singer' THEN name END) AS Singer,
    MIN(CASE WHEN occupation = 'Actor' THEN name END) AS Actor
--     You can use MIN or MAX up to you b/c It doesn't effect to the query (they are suppressed by GROUP BY rn)
FROM (SELECT
        name,
        occupation,
        ROW_NUMBER() OVER(PARTITION BY occupation ORDER BY name) AS rn
     FROM occupations) AS t1
GROUP BY rn
ORDER BY rn;