1. SELECT concat(substr(billing_date,6,2),' ',substr(billing_date,9,2)) AS JOUR,count(client_id) AS "TOTAL"
2. FROM table_billing
3. WHERE billing_date BETWEEN "2009-01-01" AND "2009-01-06"
4. GROUP BY JOUR;

1. JOUR TOTAL
2. 01 01 3886
3. 01 02 3346
4. 01 03 3312
5. 01 04 3355
6. 01 05 2999

1. SELECT concat(substr(billing_date,6,2),' ',substr(billing_date,9,2)) AS JOUR,count(client_id) AS "TOTAL"
2. FROM table_billing
3. WHERE billing_date BETWEEN "2009-01-01" AND "2009-01-06"
4. AND price <> "0"
5. GROUP BY JOUR;

1. JOUR PAYANT
2. 01 01 3684
3. 01 02 3114
4. 01 03 3132
5. 01 04 3184
6. 01 05 2776

1. JOUR GRATUIT PAYANT TOTAL
2. 01 01 202 3684 3886
3. 01 02 232 3114 3346
4. 01 03 180 3132 3312
5. 01 04 171 3184 3355
6. 01 05 223 2776 2999

SELECT DATE_FORMAT(billing_date, '%m %d') AS jour,
       SUM(IF(price>0, 1, 0)) AS payant,
       SUM(IF(price=0, 1, 0)) AS gratuit,
       Count(*) AS total
FROM table_billing
GROUP BY jour
ORDER BY jour

1. jour    payant   gratuit  total
2. 01 01   2        1        3
3. 01 02   2        2     4
4. 01 03   2        0     2
5. 01 04   0        1     1
6. 01 05   1        1     2