Puedes hacerlo de esta manera
SELECT month,
MAX(CASE WHEN unit = 'CS-1' THEN value END) `CS-1`,
MAX(CASE WHEN unit = 'CS-2' THEN value END) `CS-2`,
MAX(CASE WHEN unit = 'CS-3' THEN value END) `CS-3`
FROM
(
SELECT unit, month,
CASE month
WHEN 'JAN' THEN jan
WHEN 'FEB' THEN feb
WHEN 'MAR' THEN mar
WHEN 'APR' THEN apr
WHEN 'MAY' THEN may
WHEN 'JUN' THEN jun
END value
FROM table1 t CROSS JOIN
(
SELECT 'JAN' month UNION ALL
SELECT 'FEB' UNION ALL
SELECT 'MAR' UNION ALL
SELECT 'APR' UNION ALL
SELECT 'MAY' UNION ALL
SELECT 'JUN'
) c
) q
GROUP BY month
ORDER BY FIELD(month, 'JAN', 'FEB', 'MAR', 'APR', 'MAY', 'JUN')
Salida:
| MONTH | CS-1 | CS-2 | CS-3 | |-------|------|------|------| | JAN | 100 | 111 | 331 | | FEB | 200 | 222 | 123 | | MAR | 300 | 333 | 423 | | APR | 400 | 444 | 923 | | MAY | 500 | 555 | 918 | | JUN | 600 | 666 | 123 |
Aquí está SQLFiddle demostración
