SQL语句模糊查询总数求和平均最大最小

1、表CREATETABLE`student`(`id螬绣囤扮`int(50)NOTNULLAUTO_INCR呶蓟鹭毵EMENT,`name`varchar(50)DEFAULTNULL,`sex`varchar(48)DEFAULTNULL,`age`varchar(50)DEFAULTNULL,`birthday`varchar(50)DEFAULTNULL,PRIMARYKEY(`id`))ENGINE=InnoDBAUTO_INCREMENT=244DEFAULTCHARSET=utf8

3、总数（有几个数据）SELECT COUNT(*) FROM student

5、求平均（求年龄的平均）SELECT AVG(age) FROM student

7、求最小（求年龄最小的）SELECT MIN(age) FROM student