Web学生管理程序

目录

1、目标

1）任务需求

2）基本解析

2、代码部分

1）服务器部分

2）客户端部分

PS:

1、目标

1）任务需求

学生的记录包括学号No、姓名Name、性别Sex与年龄Age，服务器的作用是建立与维护一个Sqllite的学生数据库students.db中的学生记录表students：

create table students (No varchar(16) primary key,Name varchar(16), Sex varchar(8), Age int)

服务器建立一个Web网站，同时提供查询学生记录、增加学生记录、删除学生记录等接口服务。服务器为了与客户端通讯，建立一个opt的参数如表所示：

opt值	含义
init	初始化学生表
insert	增加学生
delete	删除学生
	获取学生记录

2）基本解析

如果客户端向服务器发送opt="init"，那么服务器创建students表，并返回是否创建成功，如果成功就返回{"msg":"OK"}；

如果客户端向服务器发送opt="insert"，同时发送No,Name,Sex,Age参数，那么服务器向数据库表插入一条学生记录，并返回是否插入成功信息，如果成功就返回{"msg":"OK"}；

如果客户端向服务器发送opt="delete"，同时发送No参数，那么服务器从数据库表中删除学号为No的一条学生记录，并返回是否删除成功的信息，如果成功就返回{"msg":"OK"}；

如果客户端不向服务器发送opt参数值，那么服务器获取所有的学生记录返回给客户端，如果成功就返回{"msg":"OK","data":rows}，其中rows是学生的记录行的列表；

2、代码部分

1）服务器部分

import flask
import sqlite3
import json

app = flask.Flask(__name__)


class StudentDB:
    def openDB(self):
        self.con = sqlite3.connect("students.db")
        self.cursor = self.con.cursor()

    def closeDB(self):
        self.con.commit()
        self.con.close()


def initTable(self):
    res = {}
    try:
        self.cursor.execute(
            "create table students (No varchar(16) primary key,Name varchar(16), Sex varchar(8), Age int)")
        res["msg"] = "OK"
    except Exception as err:
        res["msg"] = str(err)
    return res


def insertRow(self, No, Name, Sex, Age):
    res = {}
    try:
        self.cursor.execute("insert into students (No,Name,Sex,Age) values (?,?,?,?)", (No, Name, Sex, Age))
        res["msg"] = "OK"
    except Exception as err:
        res["msg"] = str(err)
    return res


def deleteRow(self, No):
    res = {}
    try:
        self.cursor.execute("delete from students where No=?", (No,))
        res["msg"] = "OK"
    except Exception as err:
        res["msg"] = str(err)
    return res


def selectRows(self):
    res = {}
    try:
        data = []
        self.cursor.execute("select * from students order by No")
        rows = self.cursor.fetchall()
        for row in rows:
            d = {}
            d["No"] = row[0]
            d["Name"] = row[1]
            d["Sex"] = row[2]
            d["Age"] = row[3]
            data.append(d)
        res["msg"] = "OK"
        res["data"] = data
    except Exception as err:
        res["msg"] = str(err)
    return res


@app.route("/", methods=["GET", "POST"])
def process():
    opt = flask.request.values.get("opt") if "opt" in flask.request.values else ""
    res = {}
    db = StudentDB()
    db.openDB()
    if opt == "init":
        res = db.initTable()
    elif opt == "insert":
        No = flask.request.values.get("No") if "No" in flask.request.values else ""
        Name = flask.request.values.get("Name") if "Name" in flask.request.values else ""
        Sex = flask.request.values.get("Sex") if "Sex" in flask.request.values else ""
        Age = flask.request.values.get("Age") if "Age" in flask.request.values else ""
        res = db.insertRow(No, Name, Sex, Age)
    elif opt == "delete":
        No = flask.request.values.get("No") if "No" in flask.request.values else ""
        res = db.deleteRow(No)
    else:
        res = db.selectRows()
    db.closeDB()
    return json.dumps(res)


if __name__ == "__main__":
    app.run()

2）客户端部分

import urllib.request
import json



class Student:
    def __init__(self, No, Name, Sex, Age):
        self.No = No
        self.Name = Name
        self.Sex = Sex
        self.Age = Age

    def show(self):
        print("%-16s %-16s %-8s %-4d" % (self.No, self.Name, self.Sex, self.Age))


students = []
url = "http://127.0.0.1:5000"


def listStudents():
    global students
    print("%-16s %-16s %-8s %-4s" % ("No", "Name", "Sex", "Age"))
    for s in students:
        s.show()


def insertStudent(s):
    global students
    i = 0
    while (i < len(students) and s.No > students[i].No):
        i = i + 1
    if (i < len(students) and s.No == students[i].No):
        print(s.No + " already exists")
        return False
    students.insert(i, s)
    return True


def deleteRow():
    global students
    No = input("No=")
    if (No != ""):
        for i in range(len(students)):
            if (students[i].No == No):
                st = ""
                try:
                    st = "No=" + urllib.request.quote(No)
                    st = st.encode()
                    content = urllib.request.urlopen(url + "?opt=delete", st)
                    st = content.readline()
                    st = json.loads(st.decode())
                    st = st["msg"]
                except Exception as exp:
                    st = str(exp)

                if (st == "OK"):
                    del students[i]
                    print("删除成功")
                else:
                    print(st)
                break


def insertRow():
    No = input("No=")
    Name = input("Name=")
    while True:
        Sex = input("Sex=")
        if (Sex == "男" or Sex == "女"):
            break
        else:
            print("Sex is not valid")
    Age = input("Age=")
    if (Age == ""):
        Age = 0
    else:
        Age = int(Age)
    if No != "" and Name != "":
        s = Student(No, Name, Sex, Age)
        for x in students:
            if (x.No == No):
                print(No + " already exists")
                return
        st = ""
        try:
            st = "No=" + urllib.request.quote(No) + "&Name=" + urllib.request.quote(
                Name) + "&Sex=" + urllib.request.quote(Sex) + "&Age=" + str(Age)
            st = st.encode()
            content = urllib.request.urlopen(url + "?opt=insert", st)
            st = content.read()
            st = json.loads(st.decode())
            st = st["msg"]
        except Exception as exp:
            st = str(exp)

        if (st == "OK"):
            insertStudent(s)
            print("增加成功")
        else:
            print(st)
    else:
        print("学号、姓名不能为空")


def initialize():
    st = ""
    try:
        content = urllib.request.urlopen(url + "?opt=init")
        st = content.read()
        st = json.loads(st.decode())
        st = st["msg"]
    except Exception as exp:
        st = str(exp)

    if (st == "OK"):
        print("初始成功")
    else:
        print(st)
    return st


def readStudents():
    global students
    try:
        students.clear()
        content = urllib.request.urlopen(url)
        data = b""
        while True:
            buf = content.read(1024)
            if (len(buf) > 0):
                data = data + buf
            else:
                break
        data = data.decode()
        data = json.loads(data)
        if data["msg"] == "OK":
            data = data["data"]
            for d in data:
                # each d is a dictionary
                s = Student(d["No"], d["Name"], d["Sex"], d["Age"])
                students.append(s)
    except Exception as exp:
        print(exp)


try:
    readStudents()

    while True:
        print("")
        print("***学生名单***")
        print("0. 初始化学生表")
        print("1. 查看学生列表")
        print("2. 增加学生记录")
        print("3. 删除学生记录")
        print("4. 退出这个程序")
        s = input("请选择(0,1,2,3,4):")
        if (s == "0"):
            initialize()
        elif (s == "1"):
            listStudents()
        elif (s == "2"):
            insertRow()
        elif (s == "3"):
            deleteRow()
        elif (s == "4"):
            break
except Exception as exp:
    print(exp)

当我们要运行的时候需要先运行服务器端再运行客户端。

PS:

如果不想通过客户端来进行数据的添加，我们可以利用Postman来连接启动的服务器，然后在postman中进行数据的添加以及修改。