基於python的學生管理系統(含數據庫版本)

這次支持連接到后台的數據庫，直接和數據庫進行交互，實現基本的增刪查改

#!/usr/bin/python3
# coding=utf-8
"""
***********************help document****************************************
Usage:
    this is a simple student grades system,now is simple
    when start the programming,you can do following operations
    enter 'a' is to insert data into database
    enter 'b' is to display all data in database
    enter 'c' is to query the specify info in database
    enter 'h' is to see this help dacument
    enter 'd' is to delete someone student's info
    enter nothing is to do nothing,you can enter again
    simple help document is: "a--insert/b--display/c--query/h--help/d--delete/''--default"
Example:
    please enter the OPcode: a  then [enter]
*****************************************************************************

"""

#引入pymysql這個庫用來連接數據據
import pymysql

#打印幫助文檔
def help_document():
    print(__doc__)

#在已有的數據庫上創建數據庫的表
def create_database():
    #在mysql中創建數據庫student_db
    db = pymysql.connect('localhost', 'root', 'root')
    name = 'student_db'
    cursor = db.cursor()
    cursor.execute('drop database if exists ' + name)
    cursor.execute('create database if not exists ' + name)
    db.close()
    #在數據庫student_db中創建數據表student_table
    db = pymysql.connect('localhost', 'root', 'root', 'student_db')
    cursor = db.cursor()
    name = 'student_table'
    cursor.execute('drop table if exists ' + name)
    sql = """create table student_table(
    name varchar(30) primary key not null,
    age  varchar(10),
    id   varchar(20),
    grade  varchar(10))"""
    cursor.execute(sql)
    db.commit()
    db.close()

#數據庫的插入
def insert_db(name,age,id,grade):
    db = pymysql.connect('localhost', 'root', 'root','student_db')
    cursor = db.cursor()
    sql = "insert into student_table (name,age,id,grade) values ('%s','%s','%s','%s')" % \
          (name,age,id,grade)
    cursor.execute(sql)
    db.commit()
    db.close()

#打印數據庫中所有數據
def display_db():
    db = pymysql.connect('localhost', 'root', 'root', 'student_db')
    cursor = db.cursor()
    sql = "select * from student_table"
    try:
        cursor.execute(sql)
        result = cursor.fetchall()
        for row in result:
            name = row[0]
            age = row[1]
            id = row[2]
            grade = row[3]
            print("name: '%s',age: '%s',id: '%s',grade: '%s'" % (name,age,id,grade))
        print("that's all diaplayed!")
    except:
        print('nothing has been displayed...')
    db.close()

#數據庫的查找
def query_db(name):
    db = pymysql.connect('localhost', 'root', 'root', 'student_db')
    cursor = db.cursor()
    sql = "select * from student_table where name = '%s' " % name
    try:
        cursor.execute(sql)
        result = cursor.fetchall()
        for row in result:
            name1 = row[0]
            age1 = row[1]
            id1 = row[2]
            grade1 = row[3]
        print("name: '%s',age: '%s',id: '%s',grade: '%s'" % \
              (name1,age1,id1,grade1))
        print('the query is over!')
    except:
        print('can not query data!')
    db.close()

#更新數據庫
def update_db(name,age,id,grade):
    db = pymysql.connect('localhost', 'root', 'root', 'student_db')
    cursor = db.cursor()
    sql = "update student_table set age = '%s',id = '%s',grade = '%s' where name = '%s'" % \
          (age,id,grade,name)
    try:
        cursor.execute(sql)
        db.commit()
        print('updated successfully!')
    except:
        print('can not update data!')
    db.close()


#數據庫的刪除
def delete_db(name):
    db = pymysql.connect('localhost', 'root', 'root', 'student_db')
    cursor = db.cursor()
    sql = "delete from student_table where name = '%s'" % name
    try:
        cursor.execute(sql)
        db.commit()
        print('delete the student info successfully!')
    except:
        print('delete failed...')
    db.close()

# 實現switch-case語句
class switch(object):
    def __init__(self, value):
        self.value = value
        self.fall = False

    def __iter__(self):
        """Return the match method once, then stop"""
        yield self.match
        raise StopIteration

    def match(self, *args):
        """Indicate whether or not to enter a case suite"""
        if self.fall or not args:
            return True
        elif self.value in args:  # changed for v1.5, see below
            self.fall = True
            return True
        else:
            return False

#建立一個學生類
class student:
    #構造函數
    def __init__(self, name, age, id, grade):
        self.next = None
        self.name = name
        self.age = age
        self.id = id
        self.grade = grade
    #每個學生可以輸出自己的信息
    def show(self):
        print('name:', self.name, ' ', 'age:', self.age, ' ', 'id:', self.id, ' ', 'grade:', self.grade)

#建立一個學生列表類
class stulist:
    #構造函數
    def __init__(self):
        self.head = student('', 0, 0, 0)
    #輸出數據庫中所有的數據
    def display(self):
        display_db()
    #新增學生數據
    def insert(self):
        print('please enter:')
        name = input('name:')
        age = input('age:')
        id = input('id:')
        grade = input('grade:')
        insert_db(name, age, id, grade)

    #查詢學生數據
    def query(self):
        name = input('please enter the name you want to query:')
        query_db(name)

    #刪除學生數據
    def delete(self):
        name = input("please enter the student'name you want to delete:")
        delete_db(name)

#主函數，程序的入口
def main():
    stulist1 = stulist()
    user_input = input('please enter the OPcode:')
    while user_input:
        print("a--insert/b--display/c--query/h--help/d--delete/''--default")
        for case in switch(user_input):
            if case('a'): #按下'a'鍵
                stulist1.insert()
                user_input = input('please enter the OPcode:')
                break
            if case('b'):  #按下'b'鍵
                stulist1.display()
                user_input = input('please enter the OPcode:')
                break
            if case('c'):  #按下'c'鍵
                stulist1.query()
                user_input = input('please enter the OPcode:')
                break
            if case('d'):  #按下'd'鍵
                stulist1.delete()
                user_input = input('please enter your OPcode:')
                break
            if case('h'):  #按下'h'鍵
                help_document()
                user_input = input('please enter your OPcode:')
                break
            if case():  # default
                print('please enter the OPcode...')
                user_input = input('please enter the OPcode:')
                break


if __name__ == "__main__":
    #第一次運行程序需要建立新的數據庫,需要運行下面注釋的一行代碼，下次運行得將其注釋掉
    #create_database()
    main()

結果效果圖：

輸入'h'查看幫助文檔

輸入'b'來查詢數據庫數據:

 

這個版本還是很粗糙，訪問速度也很慢，如果以后還有時間的話，我會做一個界面出來，改進下和數據庫的交互方式。