温江做网站,做企业网站价格,网站开发工具与技术,wordpress数据库删除以基本的学生选课为例#xff0c;建立选课数据库#xff0c;学生、班级、选课信息三张表#xff0c;并分别对表进行插删改操作#xff1a;import MySQLdbtry:conn MySQLdb.connect(host localhost, user root, passwd root, db xuanke, port 3306)cur conn.cursor()…以基本的学生选课为例建立选课数据库学生、班级、选课信息三张表并分别对表进行插删改操作import MySQLdbtry:conn MySQLdb.connect(host localhost, user root, passwd root, db xuanke, port 3306)cur conn.cursor()cur.execute(CREATE DATABASE xuanke)cur.execute(CREATE TABLE Student (Sno VARCHAR(9) PRIMARY KEY, Sname VARCHAR(20) UNIQUE, Ssex VARCHAR(2), Sage SMALLINT, Sdept VARCHAR(20)))cur.execute(CREATE TABLE Course (Cno VARCHAR(4) PRIMARY KEY, Cname VARCHAR(40), Cpno VARCHAR(4), Ccredit SMALLINT, FOREIGN KEY (Cpno) REFERENCES Course(Cno)))cur.execute(CREATE TABLE SC (Sno VARCHAR(9), Cno VARCHAR(4), Grade SMALLINT, PRIMARY KEY (Sno, Cno), FOREIGN KEY (Sno) REFERENCES Student(Sno), FOREIGN KEY (Cno) REFERENCES Course(Cno)))cur.execute(INSERT INTO Student VALUES (200215121, Stephen Zhou, M, 20, CS))cur.execute(INSERT INTO Student VALUES (200215122, Stan Qian, M, 23, CS))cur.execute(INSERT INTO Student VALUES (200215123, Linda Fan, F, 21, MA))cur.execute(INSERT INTO Student VALUES (200215125, Zac Gu, M, 26, IS))cur.execute(INSERT INTO Course VALUES (2, Math, Null, 2))cur.execute(INSERT INTO Course VALUES (6, Data Processing, Null, 2))cur.execute(INSERT INTO Course VALUES (7, PASCAL, 6, 4))cur.execute(INSERT INTO Course VALUES (5, Data Structure, 7, 4))cur.execute(INSERT INTO Course VALUES (1, Database, 5, 4))cur.execute(INSERT INTO Course VALUES (3, Information System, 1, 4))cur.execute(INSERT INTO Course VALUES (4, Operating System, 6, 3))cur.execute(INSERT INTO SC VALUES(200215121, 1, 92))cur.execute(INSERT INTO SC VALUES(200215121, 2, 85))cur.execute(INSERT INTO SC VALUES(200215121, 3, 88))cur.execute(INSERT INTO SC VALUES(200215122, 2, 90))cur.execute(INSERT INTO SC VALUES(200215122, 3, 80))cur.execute(INSERT INTO Student VALUES(200215128, Cuan Qu, M, 22, IS))cur.execute(UPDATE Student SET Sage 23 WHERE Sno 200215128)cur.execute(UPDATE Student SET Sage Sage 7)cur.execute(DELETE FROM Student WHERE Sno 200215128)cur.close()conn.commit()conn.close()except MySQLdb.Error, e:print Mysql error msg: , e显示数据库显示所建表显示学生表显示课程表显示选课信息表注以上python程序中插入操作需要一步步运行特别是课程表中‘Cpno’为先选课程其为课程表外键并与Course.Cno参照必须按顺序依次插入。
