Now working, thank you.

SELECT Coalesce( sGIG, 'Tot' ) as sGIG, Sum(Number) as Num

FROM (

SELECT LEFT (idDGIG, 2) AS sGIG, COUNT(idDGIG) AS NUMBER

FROM TABLE_LONG

WHERE

LEFT (idDGIG, 2) IN ('QM', 'QI', 'QO', 'QS')

AND DATE_START = DATE_ADD(CURDATE(), INTERVAL - 1 DAY)

GROUP BY sGIG

UNION ALL

SELECT LEFT (idDGIG, 2) AS sGIG, COUNT(idDGIG) AS NUMBER

FROM TABLE_SHORT

WHERE

LEFT (idDGIG, 2) IN ('QM', 'QI', 'QO', 'QS')

AND DATE_START = DATE_ADD(CURDATE(), INTERVAL - 1 DAY)

GROUP BY sGIG

) AS sums

Group by sGIG WITH ROLLUP;

+--------+--------+

| sGIG | NUMBER |

+--------+--------+

| QI | 11 |

| QM | 4 |

| QO | 22 |

| QS | 11 |

| Tot | 48 |

+--------+--------+