标签:esc imei strong 成绩 bsp sql 并集 png art
1.NOT IN:
mysql> select * from teacher; +---------+-------------+---------+---------------------+----------+------------+ | tea_num | tea_name | tea_sex | tea_birth | tea_prof | department | +---------+-------------+---------+---------------------+----------+------------+ | 0435 | LiMei | F | 1983-02-24 00:00:00 | prof | Computer | | 0436 | MaDi | F | 1984-01-23 00:00:00 | assist | Bio | | 0437 | LiZhe | F | 1974-01-23 00:00:00 | prof | Econ | | 0438 | ShaoGuoYing | F | 1985-06-17 00:00:00 | prof | Math | | 0439 | Susan | F | 1985-07-18 00:00:00 | assist | Math | | 0440 | Mary | F | 1990-05-02 00:00:00 | lecturer | Econ | +---------+-------------+---------+---------------------+----------+------------+
查询Math与Econ不同职称的教师的tea_name与tea_prof:
Econ中的职称类型:
mysql> select tea_prof from teacher where department in (‘Econ‘); +----------+ | tea_prof | +----------+ | prof | | lecturer | +----------+
Math中与它不同的:
mysql> select tea_name,tea_prof from teacher where department = ‘Math‘ and tea_prof not in (select tea_prof from teacher where department in (‘Econ‘)); +----------+----------+ | tea_name | tea_prof | +----------+----------+ | Susan | assist | +----------+----------+
同理:
mysql> select tea_name,tea_prof from teacher where department = ‘Econ‘ and tea_prof not in (select tea_prof from teacher where department in (‘Math‘)); +----------+----------+ | tea_name | tea_prof | +----------+----------+ | Mary | lecturer | +----------+----------+
2条结果合在一起:union求并集
mysql> select tea_name,tea_prof from teacher where department = ‘Econ‘ and tea_prof not in (select tea_prof from teacher where department in (‘Math‘)) -> union -> select tea_name,tea_prof from teacher where department = ‘Math‘ and tea_prof not in (select tea_prof from teacher where department in (‘Econ‘)); +----------+----------+ | tea_name | tea_prof | +----------+----------+ | Mary | lecturer | | Susan | assist | +----------+----------+
3.查询课程号为2-271和1-245的成绩:
mysql> select * from score where cour_num in (‘2-271‘); +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11423 | 2-271 | 75 | | 11425 | 2-271 | 89 | | 11426 | 2-271 | 82 | +---------+----------+--------+
mysql> select * from score where cour_num in (‘1-245‘); +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11423 | 1-245 | 84 | | 11426 | 1-245 | 61 | | 11427 | 1-245 | 78 | +---------+----------+--------+
any:任意一个
mysql> select * from score where cour_num=‘2-271‘ -> and degree>any(select degree from score where cour_num=‘1-245‘); +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11423 | 2-271 | 75 | | 11425 | 2-271 | 89 | | 11426 | 2-271 | 82 | +---------+----------+--------+
按成绩降序排列:
mysql> select * from score where cour_num=‘2-271‘ -> and degree>any(select degree from score where cour_num=‘1-245‘) -> order by degree desc; +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11425 | 2-271 | 89 | | 11426 | 2-271 | 82 | | 11423 | 2-271 | 75 | +---------+----------+--------+
4.all:所有
mysql> select * from score -> where cour_num=‘2-271‘ -> and degree>all(select degree from score where cour_num=‘1-245‘); +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11425 | 2-271 | 89 | +---------+----------+--------+
标签:esc imei strong 成绩 bsp sql 并集 png art
原文地址:https://www.cnblogs.com/direwolf22/p/11984248.html