python

代码片段一

连接并执行sql

#encoding:UTF-8 import MySQLdb conn = MySQLdb.Connect( host = '127.0.0.1', port = 3306, user = 'root', passwd='123456', db='imooc', charset='utf8' ) cursor = conn.cursor() print conn print cursor sql = "select * from user" cursor.execute(sql) #执行

取数据

print cursor.rowcount #取数据 #fetchone()获取一条数据 #fetchany(3)获取多条 #fetchall()#获取客户缓冲区的所有数据 # rs = cursor.fetchone() # print rs # # rs = cursor.fetchmany(2) # print rs # # rs = cursor.fetchall() # print rs # rs = cursor.fetchall() # for row in rs: # print "userid=%s,username=%s" % row

更新数据库

# sql_insert = "insert into user(userid,username) values(10,'name10')" # sql_update = "update user set username='name91' where userid=9" # sql_delete = "delete from user where userid<3" # cursor.execute(sql_insert) # cursor.execute(sql_update) # cursor.execute(sql_delete) # #执行完后提交 # conn.commit() # #发生异常时回滚 # try: # sql_insert = "insert into user(userid,username) values(10,'name10')" # sql_update = "update user set username='name91' where userid=9" # sql_delete = "delete from user where userid<3" # cursor.execute(sql_insert) # cursor.execute(sql_update) # cursor.execute(sql_delete) # conn.commit() # except Exception as e: # print e # conn.rollback() cursor.close() conn.close()

代码片段2 银行实例

#coding:UTF-8 import sys import MySQLdb class TransferMoney(object): def __init__(self,conn): self.conn = conn def tranfer(self,source_acctid,target_acctid,money): try: self.check_acct_available(source_acctid) self.check_acct_available(target_acctid) self.has_enough_money(source_acctid,money) self.reduce_money(source_acctid,money) self.add_money(target_acctid,money) self.conn.commit() except Exception as e: self.conn.rollback() raise e def check_acct_available(self, acctid): cursor = self.conn.cursor() try: sql = "select * from account where acctid=%s"