MySQL commonly used SQL statements (Python implementation of students, courses, select the timetable and additions and changes)

Taking the basic student elective course as an example, set up a database of elective courses, three tables for students, classes, and elective courses, and insert and revise the tables respectively:

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 ()  UNIQUE, Ssex  VARCHAR (2),  sage smallint, sdept varchar ()) Cur.execute ("Create table course   (Cno varchar (4)  primary key, cname varchar (+),  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 ',  ',  ' CS ') cur.execute ("insert into  student values  (' 200215122 ',  ' Stan qian ',  ' M ',  ' ",  ' CS ')") Cur.execute (" insert into student values  (' 200215123 ',  ' linda fan ',  ' F ',  ',  ' ' MA ') ") Cur.execute (" insert into student values  (' 200215125 ',  ' zac gu ',  ' M ',   ',  ' 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 ',  ')") Cur.execute ("INSERT  into sc values (' 200215121 ',  ' 2 ',  ') ') Cur.execute ("insert into sc  VALUES (' 200215121 ',  ' 3 ',  ') ") Cur.execute (" Insert into sc values (' 200215122 ',  ' 2 ',  ') 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 =  '  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

• To display the database:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/39/56/wKiom1O4-fajqnmcAACfaOj80aY929.jpg "title=" 2014-07-06-01-mysql-t-sql-01-show-databases.png "alt=" Wkiom1o4-fajqnmcaacfaoj80ay929.jpg "/>

• Show the table you built:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/39/56/wKioL1O4-h_iD7TnAATwnDZ_XOo666.jpg "title=" 2014-07-06-01-mysql-t-sql-02-desc-tablename.png "alt=" Wkiol1o4-h_id7tnaatwndz_xoo666.jpg "/>

• Show student Table:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/39/56/wKioL1O4-fHCRBEZAAE8KCqxf-s462.jpg "title=" 2014-07-06-01-mysql-t-sql-03-select-student.png "alt=" Wkiol1o4-fhcrbezaae8kcqxf-s462.jpg "/>

• Show Curriculum:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/39/56/wKiom1O4-i_iY57mAAE_tM241o0447.jpg "title=" 2014-07-06-01-mysql-t-sql-03-select-course.png "alt=" Wkiom1o4-i_iy57maae_tm241o0447.jpg "/>

• Display the Course Information table:

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/39/56/wKiom1O4-kDi1qMuAADbtxl2BqE227.jpg "title=" 2014-07-06-01-mysql-t-sql-03-select-sc.png "alt=" Wkiom1o4-kdi1qmuaadbtxl2bqe227.jpg "/>

Note: The above Python program insert operation needs to run step by step, especially in the curriculum ' Cpno ' is the first course, which is the curriculum foreign key and with course. CNO references, must be inserted sequentially.

This article is from the "Kid's Turf" blog, make sure to keep this source http://zhoufwind.blog.51cto.com/1029821/1435026