请用标准SQL完成如下题目：12以汉字属性显示student 表所记录的namesexclass列2 显示教师工作的单位不许重复3 查询成绩在60到80之间的学生学号与姓名4． 查询‘95031班级或者性别为‘女’的学生信息5．以cno升序、dlegree降序显示score中的记录6． 显示’95031’班中的学生人数7 显示3-105’号课程的平均分数8显示最低分数大于70最高分数低于90的学号

SELECT name, sex, class FROM student WHERE id = 12;

SELECT DISTINCT unit FROM teacher;

SELECT id, name FROM student WHERE score BETWEEN 60 AND 80;

SELECT * FROM student WHERE class = '95031' OR sex = '女';

SELECT * FROM score ORDER BY cno ASC, dlegree DESC;

SELECT COUNT(*) FROM student WHERE class = '95031';

SELECT AVG(score) FROM score WHERE cno = '3-105';

SELECT no FROM score GROUP BY no HAVING MIN(score) > 70 AND MAX(score) < 90;

SELECT student.name, score.cno, score.score FROM student INNER JOIN score ON student.id = score.id;

SELECT cno, AVG(score) FROM score GROUP BY cno;