5.9---python連接數據庫實現登錄注冊

使用python連接數據庫，實現賬號登錄與注冊功能

import pymysql

# MySQL語句 插入數據行，即注冊行為
register_sql = 'insert into user(name,password) values(%s,%s)'
# MySQL語句 查看name=username的數據行 判斷是否已存在該用戶
check_sql = 'select name from user where BINARY name =%s ' # 加入BINARY關鍵字，可使查詢結果區分大小寫
# check_sql = 'select name from user where name =%s '  # 這種查詢無法區分大小寫

# MySQL語句 查看所有符合該賬號與密碼的用戶  若無則有誤，若有則輸出登錄成功
login_sql = 'select * from user where name=%s and password=%s'

# 連接數據庫函數
def MySQL_conn():
    conn = pymysql.connect(
        host = "127.0.0.1",
        port = 3306,
        user = "root",
        password = "123",
        database = "day48",
        charset = "utf8",
        autocommit = True
    )   # 連接數據庫

    # 以字典形式輸出數據  不設置則默認為元組類型輸出
    cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
    return cursor

# 登錄函數
def login(cursor):
    while True:
        username = input("請輸入用戶名：").strip()
        if username.lower == "q":
            return
        password = input("請輸入密碼：").strip()

        res = cursor.execute(login_sql,(username,password))    # 返回值為數據行數，或字典鍵值對個數
        if res:
            print("登陸成功！")
            print('數據行數：',res)          # 2
            print(cursor.fetchall())        # [{'id': 1, 'name': 'Jil', 'password': '1118'}, {'id': 3, 'name': 'Jil', 'password': '1118'}]
            cursor.scroll(-1,"relative")    # 相對於光標所在的位置繼續往前移動1位
            print(cursor.fetchall())        # 光標位置取到取到最后  [{'id': 3, 'name': 'Jil', 'password': '1118'}]
            return
        else:
            print("用戶名或密碼錯誤！")

# 注冊函數
def register(cursor):
    while True:
        username = input("注冊用戶名：").strip()
        if username.lower == "q":
            return
        password = input("設定密碼：").strip()
        re_password = input("確認密碼：").strip()

        if password != re_password:
            print("兩次密碼輸入不一致，請重新輸入！")
            continue
        res = cursor.execute(check_sql,(username))
        # print(res)
        # print(cursor.fetchall())
        if res:
            print("用戶名【%s】已存在，請重新輸入！"%username)
            continue
        else:
            cursor.execute(register_sql,(username,password))
            print("注冊成功！")
            return


if __name__ == '__main__':
    cursor = MySQL_conn()
    while True:
        print("登錄或注冊".center(50,"="))
        print('''1、登錄
2、注冊''')
        cmd = input("請輸入您需要的操作數：").strip()
        if cmd not in ["1","2",'q']:
            print("請輸入正確指令！")
        if cmd == '1':
            login(cursor)
        elif cmd == '2':
            register(cursor)
        else:
            break