解决方法：

（1）请创建如下数据表（一共用七条数据做了演示，男生4条，女生3条）：

CREATE TABLE `tb_student` (
  `Fid` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
  `Fname` varchar(8) DEFAULT NULL,
  `Fsex` tinyint(1) unsigned DEFAULT '1' COMMENT '1代表男，2代表女',
  PRIMARY KEY (`Fid`)
) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of tb_student
-- ----------------------------
INSERT INTO `tb_student` VALUES ('1', '张', '1');
INSERT INTO `tb_student` VALUES ('2', '王', '1');
INSERT INTO `tb_student` VALUES ('3', '李', '1');
INSERT INTO `tb_student` VALUES ('4', '赵', '1');
INSERT INTO `tb_student` VALUES ('5', '钱', '2');
INSERT INTO `tb_student` VALUES ('6', '孙', '2');
INSERT INTO `tb_student` VALUES ('7', '江', '2');

（2）SQL语句，两种写法：

第一种：SELECT COUNT(Fsex) AS totals FROM tb_student GROUP BY Fsex HAVING totals;
第二种：SELECT SUM(Fsex=1) AS boys, SUM(Fsex=2) AS girls FROM tb_student;