python操作mysql数据库之查询的三种方式

import pymysql
from pymysql.cursors import DictCursor
conn=None
try:

    conn=pymysql.connect(
        host="127.0.0.1",
        user="root",
        password="root",
        database="my_news",
        port=3306,
        cursorclass=DictCursor  # 打印出的就是字典的形式
    )
    with conn:
        with conn.cursor() as cursor:
            sql="select * from  user;"
            cursor.execute(sql)
            # 第一种方式查看
            # for item in cursor:
            #     print(item)
            # 第二种方式
            # text=cursor.fetchone()
            # print(text)
            # text = cursor.fetchall()
            # for item in text:
            #
            #     print(item)
            text = cursor.fetchmany(5)
            for item in text:
                print(item)
except Exception as e:
    print(e)
finally:
    try:
        conn.close()
        print("数据库链接已经关闭")
    except Exception as e:
        print("数据库关闭失败")

-

-来自百度网盘超级会员V2的分享

hi，这是我用百度网盘分享的内容~复制这段内容打开「百度网盘」APP即可获取 

链接:https://pan.baidu.com/s/1gIFlzdveT2ml-2CVNxs-4g 

提取码:s99d