Python3.6简单的操作Mysql数据库的三个实例

import pymysql# 创建连接# 参数依次对应服务器地址，用户名，密码，数据库conn = pymysql.connect(host='127.0.0.1', user='root', passwd='123456', db='demo')# 创建游标cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)# 执行语句返回影响的行数effect_row = cursor.execute("select * from course")print(effect_row)# 获取所有数据result = cursor.fetchall()result = cursor.fetchone() # 获取下一个数据result = cursor.fetchone() # 获取下一个数据（在上一个的基础之上）# cursor.scroll(-1, mode='relative') # 相对位置移动# cursor.scroll(0,mode='absolute') # 绝对位置移动# 提交，不然无法保存新建或者修改的数据conn.commit()# 关闭游标cursor.close()# 关闭连接conn.close()

import pymysql# 建立连接conn = pymysql.connect(host='127.0.0.1', user='root', passwd='123456', db='demo')# 创建游标cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)# 插入一条数据 %s是占位符 占位符之间用逗号隔开effect_row = cursor.execute("insert into course(cou_name,time) values(%s,%s)", ("Engilsh", 100))print(effect_row)conn.commit()cursor.close()conn.close()

import pymysql.cursors# Connect to the databaseconnection = pymysql.connect(host='localhost',        user='user',        password='passwd',        db='db',        charset='utf8mb4',        cursorclass=pymysql.cursors.DictCursor)try: with connection.cursor() as cursor:  # Create a new record  sql = "INSERT INTO `users` (`email`, `password`) VALUES (%s, %s)"  cursor.execute(sql, ('webmaster@python.org', 'very-secret')) # connection is not autocommit by default. So you must commit to save # your changes. connection.commit() with connection.cursor() as cursor:  # Read a single record  sql = "SELECT `id`, `password` FROM `users` WHERE `email`=%s"  cursor.execute(sql, ('webmaster@python.org',))  result = cursor.fetchone()  print(result)finally: connection.close()