pymysql.Connect()参数说明

host(str):      MySQL服务器地址

port(int):      MySQL服务器端口号

user(str):      用户名

passwd(str):    密码

db(str):        数据库名称

charset(str):   连接编码

connection对象支持的方法

cursor()        使用该连接创建并返回游标

commit()        提交当前事务

rollback()      回滚当前事务

close()         关闭连接

cursor对象支持的方法

execute(op)     执行一个数据库的查询命令

fetchone()      取得结果集的下一行

fetchmany(size) 获取结果集的下几行

fetchall()      获取结果集中的所有行

rowcount()      返回数据条数或影响行数

close()         关闭游标对象

CREATE TABLE `trade` (

  `id` int(4) unsigned NOT NULL AUTO_INCREMENT,

  `name` varchar(6) NOT NULL COMMENT '用户真实姓名',

  `account` varchar(11) NOT NULL COMMENT '银行储蓄账号',

  `saving` decimal(8,2) unsigned NOT NULL DEFAULT '0.00' COMMENT '账户储蓄金额',

  `expend` decimal(8,2) unsigned NOT NULL DEFAULT '0.00' COMMENT '账户支出总计',

  `income` decimal(8,2) unsigned NOT NULL DEFAULT '0.00' COMMENT '账户收入总计',

  PRIMARY KEY (`id`),

  UNIQUE KEY `name_UNIQUE` (`name`)

) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

INSERT INTO `trade` VALUES (1,'乔布斯','',0.00,0.00,0.00);

import pymysql.cursors

# 连接数据库

connect = pymysql.Connect(

    host='192.168.11.200',

    port=3306,

    user='root',

    passwd='root',

    db='db5',

    charset='utf8'

)

# 获取游标

cursor = connect.cursor()

# 插入数据

sql = "INSERT INTO trade (name, account, saving) VALUES ( '%s', '%s', %.2f )"

data = ('雷军', '', 10000)

cursor.execute(sql % data)

connect.commit()

print('成功插入', cursor.rowcount, '条数据')

# 修改数据

sql = "UPDATE trade SET saving = %.2f WHERE account = '%s' "

data = (8888, '')

cursor.execute(sql % data)

connect.commit()

print('成功修改', cursor.rowcount, '条数据')

# 查询数据

sql = "SELECT name,saving FROM trade WHERE account = '%s' "

data = ('',)

cursor.execute(sql % data)

for row in cursor.fetchall():

    print("Name:%s\tSaving:%.2f" % row)

print('共查找出', cursor.rowcount, '条数据')

# 删除数据

sql = "DELETE FROM trade WHERE account = '%s' LIMIT %d"

data = ('', 1)

cursor.execute(sql % data)

connect.commit()

print('成功删除', cursor.rowcount, '条数据')

# 事务处理

sql_1 = "UPDATE trade SET saving = saving + 1000 WHERE account = '18012345678' "

sql_2 = "UPDATE trade SET expend = expend + 1000 WHERE account = '18012345678' "

sql_3 = "UPDATE trade SET income = income + 2000 WHERE account = '18012345678' "

try:

    cursor.execute(sql_1)  # 储蓄增加1000

    cursor.execute(sql_2)  # 支出增加1000

    cursor.execute(sql_3)  # 收入增加2000

except Exception as e:

    connect.rollback()  # 事务回滚

    print('事务处理失败', e)

else:

    connect.commit()  # 事务提交

    print('事务处理成功', cursor.rowcount)

# 关闭连接

cursor.close()

connect.close()