摘要:
SET NAMES utf8;SET FOREIGN_KEY_CHECKS = 0; -- Table structure for `class`-- DROP TABLE IF EXISTS `class`;CREATE TABLE `class` ( `cid` int(11) NOT NULL 阅读全文
摘要:
14、查询每门课程被选修的次数 SELECT course_id,COUNT(sid) FROM score GROUP BY course_id 15、查询之选修了一门课程的学生姓名和学号 SELECT sname FROM student WHERE sid in ( SELECT studen 阅读全文