python怎么操作mysql

pip install pymysql

import pymysql  #导入 pymysql ，如果编译未出错，即表示 pymysql 安装成功

import pymysql  #导入 pymysql

#打开数据库连接

db= pymysql.connect(host="localhost",user="root",

     password="123456",db="test",port=3307)

# 使用cursor()方法获取操作游标

cur = db.cursor()

#1.查询操作

# 编写sql 查询语句  user 对应我的表名

sql = "select * from user"

try:

    cur.execute(sql)     #执行sql语句

    results = cur.fetchall()    #获取查询的所有记录

    print("id","name","password")

    #遍历结果

    for row in results :

        id = row[0]

        name = row[1]

        password = row[2]

        print(id,name,password)

except Exception as e:

    raise e

finally:

    db.close()    #关闭连接

import pymysql

#2.插入操作

db= pymysql.connect(host="localhost",user="root",

     password="123456",db="test",port=3307)

# 使用cursor()方法获取操作游标

cur = db.cursor()

sql_insert ="""insert into user(id,username,password) values(4,'liu','1234')"""

try:

    cur.execute(sql_insert)

    #提交

    db.commit()

except Exception as e:

    #错误回滚

    db.rollback()

finally:

    db.close()

#3.更新操作

db= pymysql.connect(host="localhost",user="root",

     password="123456",db="test",port=3307)

# 使用cursor()方法获取操作游标

cur = db.cursor()

sql_update ="update user set username = '%s' where id = %d"

try:

    cur.execute(sql_update % ("xiongda",3))  #像sql语句传递参数

    #提交

    db.commit()

except Exception as e:

    #错误回滚

    db.rollback()

finally:

    db.close()

import pymysql

#4.删除操作

db= pymysql.connect(host="localhost",user="root",

     password="123456",db="test",port=3307)

# 使用cursor()方法获取操作游标

cur = db.cursor()

sql_delete ="delete from user where id = %d"

try:

    cur.execute(sql_delete % (3))  #像sql语句传递参数

    #提交

    db.commit()

except Exception as e:

    #错误回滚

    db.rollback()

finally:

    db.close()