Query join

Hi there, hope in your help.

In my DB MySQL I've two tables: TABLE_LONG and TABLE_SHORT.
The two tables are equal but in TABLE_LONG a recording long events and in TABLE_SHORT a recording short events.

If count number of long events, I've this output:

mysql> SELECT
COALESCE (idDGIG, 'Tot') AS sGIG,
`NUMBER`
FROM
(
SELECT
LEFT (idDGIG, 2) AS idDGIG,
COUNT(idDGIG) AS NUMBER
FROM
TABLE_LONG
WHERE
1
AND (
LEFT (idDGIG, 2) LIKE '%QM%'
OR LEFT (idDGIG, 2) LIKE '%QI%'
OR LEFT (idDGIG, 2) LIKE '%QO%'
OR LEFT (idDGIG, 2) LIKE '%QS%'
)
AND DATE_START = DATE_ADD(CURDATE(), INTERVAL - 1 DAY)
GROUP BY
LEFT (idDGIG, 2) WITH ROLLUP
) AS Q;+--------+--------+
| sGIG | NUMBER |+--------+--------+
| QI | 9 |
| QM | 2 |
| QO | 6 |
| QS | 5 |
| Tot | 22 |+--------+--------+
5 rows in set

If count number of short events, I've this output:

mysql> SELECT
COALESCE (idDGIG, 'Tot') AS sGIG,
NUMBER
FROM
(
SELECT
LEFT (idDGIG, 2) AS sGIG,
COUNT(idDGIG) AS NUMBER
FROM
TABLE_SHORT
WHERE
1
AND (
LEFT (idDGIG, 2) LIKE '%QM%'
OR LEFT (idDGIG, 2) LIKE '%QI%'
OR LEFT (idDGIG, 2) LIKE '%QO%'
OR LEFT (idDGIG, 2) LIKE '%QS%'
)
AND DATE_START = DATE_ADD(CURDATE(), INTERVAL - 1 DAY)
GROUP BY
LEFT (idDGIG, 2) WITH ROLLUP
) AS Z;
+--------+-----------+
| sGIG | NUMBER |
+--------+-----------+
| QI | 2 |
| QM | 2 |
| QO | 16 |
| QS | 6 |
| Tot | 26 |
+--------+-----------+
5 rows in set

Now I need tried join two tables with this query; I think in output total events ( long + short ): 22+26 = 48.
Instead I've this wrong output (1144), why?
Can you help me.
Thanks in advance.

mysql> SELECT
DATE_START,
COALESCE (idDGIG, 'Tot') AS sGIG,
`NUMBER`
FROM
(
SELECT
CA.DATE_START AS DATE_START,
LEFT (CA.idDGIG, 2) AS sGIG,
COUNT(CA.idDGIG) + COUNT(A.EVENT) AS NUMBER
FROM
TABLE_LONG CA
JOIN TABLE_SHORT A ON CA.DATE_START = A.DATE_START
WHERE
CA.DATE_START = DATE_ADD(CURDATE(), INTERVAL - 1 DAY)
AND (
LEFT (CA.idDGIG, 2) LIKE '%QM%'
OR LEFT (CA.idDGIG, 2) LIKE '%QI%'
OR LEFT (CA.idDGIG, 2) LIKE '%QO%'
OR LEFT (CA.idDGIG, 2) LIKE '%QS%'
)
GROUP BY
LEFT (CA.idDGIG, 2) WITH ROLLUP
) AS SSS;
+-------------+--------+--------+
| DATE_START | sGIG | NUMBER |
+-------------+--------+--------+
| 2013-03-27 | QI | 468 |
| 2013-03-27 | QM | 104 |
| 2013-03-27 | QO | 312 |
| 2013-03-27 | QS | 260 |
| 2013-03-27 | Tot | 1144 |
+-------------+--------+--------+
5 rows in set