1) ALTER TABLE student ADD 专业 C(10) 2) INSERT INTO student(学号,姓名,性别,年龄) ; VALUES('20011228','王刚','男',21) 3) SELECT AVG(年龄) as 平均年龄 FROM student WHERE 性别="男" 4) SELECT MIN(年龄) as 最小年龄 FROM student WHERE 性别="女" 5) SELECT 姓名,性别,年龄 FROM student WHERE 姓名 like "李%" 6) UPDATE student SET 成绩=成绩+10 WHERE 民族<>"汉" 7) DELETE FROM student WHERE 成绩 is null 8) SELECT * FROM student ORDER BY 成绩 DESC