--------------
DESCRIBE titanic
--------------

+-------+------------+------+-----+---------+-------+
| Field | Type       | Null | Key | Default | Extra |
+-------+------------+------+-----+---------+-------+
| IDEN  | varchar(5) |      |     |         |       |
| CLASS | int(6)     |      |     | 0       |       |
| AGE   | int(9)     |      |     | 0       |       |
| SEX   | int(9)     |      |     | 0       |       |
| SURV  | int(10)    |      |     | 0       |       |
+-------+------------+------+-----+---------+-------+
5 rows in set (0.00 sec)

--------------
SELECT COUNT(*) FROM titanic
--------------

+----------+
| COUNT(*) |
+----------+
|     2201 |
+----------+
1 row in set (0.00 sec)

--------------
SELECT COUNT(*) FROM titanic WHERE surv=1
--------------

+----------+
| COUNT(*) |
+----------+
|      711 |
+----------+
1 row in set (0.00 sec)

--------------
SELECT 100*COUNT(*)/2201 FROM titanic WHERE surv=1
--------------

+-------------------+
| 100*COUNT(*)/2201 |
+-------------------+
|             32.30 |
+-------------------+
1 row in set (0.00 sec)

--------------
SELECT COUNT(*)," hommes" FROM titanic WHERE sex=1
--------------

+----------+---------+
| COUNT(*) |  hommes |
+----------+---------+
|     1731 |  hommes |
+----------+---------+
1 row in set (0.00 sec)

--------------
SELECT COUNT(*)," femmes" FROM titanic WHERE sex=0
--------------

+----------+---------+
| COUNT(*) |  femmes |
+----------+---------+
|      470 |  femmes |
+----------+---------+
1 row in set (0.00 sec)


--------------
SELECT ROUND(100*COUNT(sex)/2201) AS frq ,
        "%", IF(sex=0,"femmes","hommes")
        FROM titanic GROUP BY sex ORDER BY frq DESC
--------------

+------+---+--------+
| frq  | % | sexe   |
+------+---+--------+
|   79 | % | hommes |
|   21 | % | femmes |
+------+---+--------+
2 rows in set (0.01 sec)

--------------
SELECT COUNT(*) FROM titanic WHERE NOT (sex=0 OR sex=1)
--------------

+----------+
| COUNT(*) |
+----------+
|        0 |
+----------+
1 row in set (0.00 sec)

--------------
SELECT 100*COUNT(*)/470 FROM titanic WHERE sex=0 AND surv=1
--------------

+------------------+
| 100*COUNT(*)/470 |
+------------------+
|            73.19 |
+------------------+
1 row in set (0.01 sec)

--------------
SELECT ROUND(100*COUNT(*)/1731) FROM titanic WHERE (sex=1 AND surv=1)
--------------

+--------------------------+
| round(100*COUNT(*)/1731) |
+--------------------------+
|                       21 |
+--------------------------+
1 row in set (0.00 sec)

Bye