Mu class python Operations database 2 example of bank transfer

CREATE TABLE' account ' (' Acctid ' )int( One)DEFAULT NULLCOMMENT'Account ID',  ` Money`int( One)DEFAULT NULLCOMMENT'Balance') ENGINE=InnoDBDEFAULTCHARSET=Utf8

1 #Coding:utf82 3 ImportMySQLdb4 ImportSYS5 6 classTransferMoney (object):7     """docstring for TransferMoney"""8     def __init__(SELF, conn):9Self.conn =ConnTen  One     defcheck_acct_avaiable (self,acctid): Acursor =self.conn.cursor () -         Try: -sql ="SELECT * from account where Acctid =%s"%Acctid the cursor.execute (SQL) -             Print "check_acct_avaiable:"+SQL -rs =Cursor.fetchall () -             ifLen (rs)! = 1: +                 RaiseException ("account%s does not exist"%Acctid) -         finally: + cursor.close () A  at     defHas_enough_money (Self,acctid,money): -cursor =self.conn.cursor () -         Try: -sql ="SELECT * from account where Acctid =%s and money >%s"%(Acctid,money) - cursor.execute (SQL) -             Print "Has_enough_money:"+SQL inrs =Cursor.fetchall () -             ifLen (rs)! = 1: to                 RaiseException ("account%s does not have enough money"%Acctid) +         finally: - cursor.close () the  *     defReduce_money (Self,acctid,money): $cursor =self.conn.cursor ()Panax Notoginseng         Try: -sql ="Update account Set money = Money-%s where Acctid =%s"%(Money,acctid) the cursor.execute (SQL) +             Print "Reduce_money:"+SQL A             ifCursor.rowcount! = 1: the                 RaiseException ("account%s failed to reduce payment"%Acctid) +         finally: - cursor.close () $  $     defAdd_money (Self,acctid,money): -cursor =self.conn.cursor () -         Try: thesql ="Update account Set Money = Money +%s where Acctid =%s"%(Money,acctid) - cursor.execute (SQL)Wuyi             Print "Add_money:"+SQL the             ifCursor.rowcount! = 1: -                 RaiseException ("Account%s bonus failed"%Acctid) Wu         finally: - cursor.close () About  $     defTransfer (Self,source_acctid,target_acctid,money): -         Try: - self.check_acct_avaiable (Source_acctid) - self.check_acct_avaiable (Target_acctid) A Self.has_enough_money (Source_acctid,money) + Self.reduce_money (Source_acctid,money) the Self.add_money (Target_acctid,money) - Self.conn.commit () $         exceptException, E: the Self.conn.rollback () the             Raisee the  the          -          in  the if __name__=="__main__": theSource_acctid = sys.argv[1] AboutTarget_acctid = sys.argv[2] theMoney = Sys.argv[3] the  theconn =MySQLdb.connect ( +Host ='127.0.0.1', -Port = 3306, theuser ='njczy2010',Bayipasswd ='57040516', thedb ='Czy', theCharSet ='UTF8' -     ) -  theTr_money =TransferMoney (conn) the  the     Try: the Tr_money.transfer (Source_acctid,target_acctid,money) -     exceptException as E: the         Print "problems occurred"+Str (e) the     finally: theConn.close ()

Correct situation:

Check_acct_avaiable:Select *  fromAccountwhereAcctid=  Onecheck_acct_avaiable:Select *  fromAccountwhereAcctid=  AHas_enough_money:Select *  fromAccountwhereAcctid=  One  and  Money >  -Reduce_money:UpdateAccountSet  Money =  Money -  - whereAcctid=  OneAdd_money:UpdateAccountSet  Money =  Money +  - whereAcctid=  A

Error condition:

Check_acct_avaiable:Select *  fromAccountwhereAcctid=  Onecheck_acct_avaiable:Select *  fromAccountwhereAcctid=  AHas_enough_money:Select *  fromAccountwhereAcctid=  One  and  Money >  -There is a problem account 11 not enough money

Mu class python Operations database 2 example of bank transfer