python操作數據庫的基本步驟：
首先打開local，
，創建qqq數據庫。
新建查詢，輸入sql語句創建sh_users表
1 create table sh_users( 2 id int unsigned primary key auto_increment not null, 3 username varchar(20) not null, 4 password char(40) not null, 5 is_delete bit default 0
6 )
刷新表頁面，輸入sql語句嘗試插入
1 insert into sh_users (username, password) values ('r速22t', 'f74e2')
接下來就可以寫代碼了！
1 from hashlib import *
2 import pymysql 3
4
5 # 獲取數據庫連接對象
6 def mysql_conn(): 7 conn = pymysql.connect(host='127.0.0.1', user='root', passwd='111111', db='qqq') 8 return conn 9
10
11 def register(): 12 try: 13 # 獲取數據庫連接對象
14 conn = mysql_conn() 15 # 獲取數據庫操作cursor（游標）
16 cur = conn.cursor() 17 # 編寫查詢的sql語句
18 select_sql = f'select password from sh_users where username = "{u_name}"'
19 # 執行sql語句
20 cur.execute(select_sql) 21 # 獲取執行結果 fetch_one()，判斷結果
22 res = cur.fetchone() 23 # 如果res返回None 表示沒有找到數據，不存在可注冊，存在注冊失敗
24 if res is not None: 25 print('用戶名已存在，注冊失敗', res) 26 else: 27 print('該用戶名可以使用') 28 # 注冊-> 插入數據，手動commit
29 insert_sql = 'insert into sh_users (username, password) values (%s,%s)'
30 insert_params = [u_name, sha_pwd] 31 cur.execute(insert_sql, insert_params) 32 conn.commit() 33 print('注冊成功', u_name) 34 # 關閉連接
35 cur.close() 36 conn.close() 37 except Exception as e: 38 print(e) 39
40
41 def login(): 42 try: 43 conn = mysql_conn() 44 cur = conn.cursor() 45 select_sql = f'select password from sh_users where username = "{u_name}"'
46 cur.execute(select_sql) 47 res = cur.fetchone() 48 if res is None: 49 # 登錄：根據用戶名沒有獲取密碼
50 print('用戶名錯誤，登錄失敗') 51 else: 52 # res有值，用戶名正確，判斷密碼正確與否
53 m_pwd = res[0] 54 print(m_pwd, '===========================') 55 if m_pwd == sha_pwd: 56 print('登錄成功', u_name) 57 else: 58 print('密碼錯誤，登錄失敗') 59 # 關閉連接
60 cur.close() 61 conn.close() 62 except Exception as e: 63 print(e) 64
65
66 if __name__ == '__main__': 67 u_name = input('請輸入用戶名') 68 u_pwd = input('請輸入密碼') 69
70 # sha1加密
71 s1 = sha1() 72 s1.update(u_pwd.encode()) 73 sha_pwd = s1.hexdigest() 74 print(sha_pwd) 75
76 # register()
77 login()
這里用了兩種字符串格式化操作，sql語句里“=”號后的引號要注意