Hi ALL,
There is a grogram to consume messages from queue; according to the message,
the program will READ a row and then UPDATE the row;
BUT, sometimes, the UPDATE statement is fail, the result of READ statement is
also the old content before UDPATE.
Any suggestions from you are appreciated.
The following are my program and the result.
---READ----
from cassandra.query import SimpleStatement
from cassandra import ConsistencyLevel
self.interval_data_get_simple = SimpleStatement("""SELECT TRADETIME,
OPENPRICE, HIGHPRICE, \
LOWPRICE, CLOSEPRICE, CHANGE, CHANGERATIO,
VOLUME, AMOUNT,SECURITYNAME, \
SECURITYID from {} WHERE SYMBOL = '{}' AND
TRADETIME = '{}';\
""".format(self.cassandra_table, symbol, \
interval_trade_time.strftime(u'%Y-%m-%d
%H:%M:%S')), \
consistency_level=ConsistencyLevel.ALL)
cur_interval_future =
self.cassandra_session.execute_async(self.interval_data_get_simple)
-----UPDATE--------
from cassandra.query import SimpleStatement
from cassandra import ConsistencyLevel
data_set_simple = SimpleStatement("""UPDATE {} SET OPENPRICE = {},
HIGHPRICE = {}, LOWPRICE = {},\
CLOSEPRICE = {}, VOLUME = {}, AMOUNT = {}, MARKET = {}, SECURITYID
= {} WHERE \
SYMBOL = '{}' AND TRADETIME =
'{}';""".format(self.cassandra_table, insert_data_list[0], \
insert_data_list[1], insert_data_list[2],
insert_data_list[3], \
insert_data_list[4], insert_data_list[5],
insert_data_list[6], \
insert_data_list[7], insert_data_list[8],
insert_data_list[9]), \
consistency_level=ConsistencyLevel.ALL)
update_future = self.cassandra_session.execute(data_set_simple)
------------test result----------
#CQL UPDATE statement
UPDATE GTA_HFDCS_SSEL2.SSEL2_TRDMIN01_20141127 SET OPENPRICE = 8.460, HIGHPRICE
= 8.460, LOWPRICE = 8.460, CLOSEPRICE = 8.460, VOLUME = 1500,
AMOUNT = 12240.000, MARKET = 1, SECURITYID = 201000003592 WHERE
SYMBOL = '600256' AND TRADETIME = '2014-11-27 10:00:00';
#the result of READ
[Row(tradetime=datetime.datetime(2014, 11, 27, 2, 0),
openprice=Decimal('8.460'), highprice=Decimal('8.460'),
lowprice=Decimal('8.460'), closeprice=Decimal('8.460'), change=None,
changeratio=None, volume=1500, amount=Decimal('12240.000'), securityname=None,
securityid=201000003592)]
#CQL UPDATE statement
UPDATE GTA_HFDCS_SSEL2.SSEL2_TRDMIN01_20141127 SET OPENPRICE = 8.460, HIGHPRICE
= 8.460, LOWPRICE = 8.160, CLOSEPRICE = 8.160, VOLUME = 3500,
AMOUNT = 28560.000, MARKET = 1, SECURITYID = 201000003592 WHERE
SYMBOL = '600256' AND TRADETIME = '2014-11-27 10:00:00';
#the result of READ
[Row(tradetime=datetime.datetime(2014, 11, 27, 2, 0),
openprice=Decimal('8.460'), highprice=Decimal('8.460'),
lowprice=Decimal('8.460'), closeprice=Decimal('8.460'), change=None,
changeratio=None, volume=1500, amount=Decimal('12240.000'), securityname=None,
securityid=201000003592)]
Thanks & Regards,
鄢来琼 / Peter YAN, Staff Software Engineer,
A3 Dept., GTA Information Technology Co., Ltd.
=========================================
Mobile: 18620306659
E-Mail: laiqiong....@gtafe.com
Website: http://www.gtafe.com/
=========================================
