Mysql学习日记-04pymysql的运用

Posted 2020-12-13 kangkang1999

pymysql模块：
　　pip3 install pymysql -i https://pypi.douban.com/simple
　　Python模块：对数据库进行操作（SQL语句）

　　1. Python实现用户登录
　　2. MySQL保存数据


- 连接、关闭（游标）
- execute() -- SQL注入
- 增删改： conn.commit()
- 查 fetchone fetchall
- 获取插入数据自增ID

 

m1.py m2.py 

import pymysql

user = input("username:")
# sql 注入 username：(asdnaosjd‘ 1=1 -- )
pwd = input("password:")

conn= pymysql.connect(host="127.0.0.1", user= ‘root‘, password=‘123456‘, database=‘day4‘)
cursor = conn.cursor()

sql = "select * from exp1 where username =‘%s‘ and password = ‘%s‘"%(user, pwd,)
cursor.execute(sql)
result= cursor.fetchone()

cursor.close()
conn.close()

if result:
    print("successful")
else:
    print("fault")


 m2.py 

import pymysql

user = input("username:")
pwd = input("password:")

conn= pymysql.connect(host="127.0.0.1", user= ‘root‘, password=‘123456‘, database=‘day4‘)
cursor = conn.cursor()

sql = "select * from exp1 where username =‘%s‘ and password = ‘%s‘"
cursor.execute(sql,user, pwd)
result= cursor.fetchone()

cursor.close()
conn.close()

if result:
    print("successful")
else:
    print("fault")

m3.py

import pymysql
# 增，删，改
# user = ‘123‘
# pwd = ‘123‘
conn= pymysql.connect(host="127.0.0.1", user= ‘root‘, password=‘123456‘, database=‘day4‘)
cursor = conn.cursor()
# sql = "insert into exp1 (username, password ) value (‘ll‘,‘123‘) "
sql = "insert into exp1 (username, password ) value (%s,%s) "
# 受影响的行数
#r = cursor.execute(sql,(user, pwd,))
r = cursor.executemany(sql, [(‘wi‘,‘123‘),(‘wq‘,‘123‘)])
conn.commit()
cursor.close()
conn.close()

# 查
conn= pymysql.connect(host="127.0.0.1", user= ‘root‘, password=‘123456‘, database=‘day4‘)
cursor = conn.cursor(cursor= pymysql.cursors.DictCursor)
sql = "select * from exp1"
cursor.execute(sql)

result = cursor.fetchone()
# print( result)
# result = cursor.fetchall()
# print(result)

cursor.close()
conn.close()


# 新插入数据的自增id
conn= pymysql.connect(host="127.0.0.1", user= ‘root‘, password=‘123456‘, database=‘day4‘)
cursor = conn.cursor()

sql = "insert into exp1(username,password) value (‘1132‘ ,  ‘1‘)"
cursor.execute(sql)
print(cursor.lastrowid)

conn.commit()
cursor.close()
conn.close()