pymysql操作MySQL数据库

一、查询数据库中的数据

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import pymysql

#打开数据库连接
conn = pymysql.connect(host="localhost", user="root", password="admin@163.com",
                       port=3306, db="db1")

#使用cursor()方法获取操作游标
cursor = conn.cursor()

#查询操作
sql = "select * from tab1"
try:
    cursor.execute(sql) #执行sql语句

    results = cursor.fetchall()  #获取查询的所有记录
    print("id", "name", "email")

    #遍历结果
    for row in results:
        id = row[0]
        name = row[1]
        email = row[2]
        print(id, name, email)
except Exception as e:
    raise e

finally:
    cursor.close()  #关闭游标
    conn.close()  #关闭连接

二、向数据库中插入数据

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import pymysql

#连接数据库
conn = pymysql.connect(host="localhost", user="root", password="admin@163.com",
                       port=3306, db="db1")

#使用cursor()方法获取游标
cursor = conn.cursor()

sql_insert = """insert into tab1(nid, name, email) values (4, 'tt', 'tt@163.com')"""

try:
    cursor.execute(sql_insert)

    #提交数据
    conn.commit()

except Exception as e:
    #错误回滚
    conn.rollback()

finally:
    cursor.close()
    conn.close()

三、更新数据库中的数据

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import pymysql

#打开数据库连接
conn = pymysql.connect(host="localhost", user="root", password="admin@163.com",
                       port=3306, db="db1")
#使用cursor()方法获取操作游标
cursor = conn.cursor()
# 更新操作
sql_update = """update tab1 set email='yusheng_liang08@163.com' where nid='1'"""

try:
    cursor.execute(sql_update)

    conn.commit()

except Exception as e:
    conn.rollback()

finally:
    cursor.close()
    conn.close()

四、删除数据库中的数据

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import pymysql

#打开数据库连接
conn = pymysql.connect(host="localhost", user="root", password="admin@163.com",
                     port=3306, db="db1")
#使用cursor()方法获取操作游标
cursor = conn.cursor()
#删除操作
sql_delete = "delete from tab1 where name='tt'"
try:

    cursor.execute(sql_delete)
    conn.commit()  #提交数据

except Exception as e:
    conn.rollback()

finally:
    cursor.close()
    conn.close()