day45MySQL--- pymysql模块

Pymysql模块的使用：

Import pymysql

#发起连接

Conn = pymysql.connect(

host=”127.0.0.1”,#1先写自己ip

port=3306,#2 mysql的端口默认3306

user = “root”,#3用户名

Password =”123”,#4密码

Database =”day45”,#5打开一个库

Charset =”utf8”#编码

Cur=conn.cursor()#拿到游标

#增、删、改

增：1#  Cur.execute(‘insert into userinfo(user,password) values (“%s”,”%s”);’%(“alex”,123))

#括号内必须是单引号

2#  insert_sql = ‘insert into userinfo(user,pawssword) values(%s,%s);’

#%s不需要加双引号

Cur.execute(insert_sql,(“alex”,”123”)

删：delete_sql=‘delete from day45.t1 id =1;’

Cur.execute(delete_sql)

改：update_sql=update day45.t1 set name=’alex’ where id =3;

Cur.execute(update_sql)

查：select_sql=select * from day45.t1 where post =’teacher’;

Cur.execute(select.sql)

Cur.fetchone()#拿出一个结果

Cur.fetchall()#拿出剩余的

Cur.fetchmany(2)#可以取两条

 pip3 install pymysql pycharm先装取pymysql模块

import pymysql
conn= pymysql.connect(host ="127.0.0.1",
                      port=3306,
                      user="root",
                      password ="123",
                      database ="day45",
                      charset="utf8"
)
cur =conn.cursor()
# cur.execute('insert into userinfo(user,password)values("%s","%s");'%("alex",123))
#增：
# insert_sql ='insert into userinfo(user,password)values(%s,%s);'
# cur.execute(insert_sql,("aaa","123"))
#删
# insert_sql='delete from day45.userinfo where id=3'
# cur.execute(insert_sql)
#改
# insert_sql='update day45.userinfo set user="bbb"where id=1'
# cur.execute(insert_sql)
#查看密码是否正确
name1=input("请输入名字：").strip()
password =input("请输入密码：").strip()
insert_sql ='select id from userinfo where user =%s and password=%s; '
rows =cur.execute(insert_sql,(name1,password))
print(cur.fetchall())
print(rows)
if rows:
    print("登陆成功")
    #直接查看数据库的内容
    select_sql='select * from day43.money where name=%s;'
    cur.execute(select_sql,(name1))
    print(cur.fetchmany()[0][2])
else:
    print("登录失败")
conn.commit()
cur.close()
conn.close()