新建数据库
插入数据
处理表
1.
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3.
mysql> alter table sc add unique index SC_INDEX (sno asc,cno asc);
4.
mysql> create view stu_info as select student.sno,ssex,sc.cno,score from student join sc on student.sno=sc.sno;
5.
mysql> drop index SC_INDEX on sc;
mysql> drop index index_cno on course;