本文实例讲述了Python sqlite3事务处理方法。分享给大家供大家参考，具体如下：
sqlite3事务总结:
在connect()中不传入 isolation_level
事务处理:
使用connection.commit()
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#!/usr/bin/env python
# -*- coding:utf-8 -*-
'''sqlite3事务总结:
在connect()中不传入 isolation_level
事务处理:
使用connection.commit()
分析:
智能commit状态:
生成方式: 在connect()中不传入 isolation_level, 此时isolation_level==''
在进行 执行Data Modification Language (DML) 操作(INSERT/UPDATE/DELETE/REPLACE)时, 会自动打开一个事务,
在执行 非DML, 非query (非 SELECT 和上面提到的)语句时, 会隐式执行commit
可以使用 connection.commit()方法来进行提交
注意:
不能和cur.execute("COMMIT")共用
自动commit状态:
生成方式: 在connect()中传入 isolation_level=None
这样,在任何DML操作时,都会自动提交
事务处理
connection.execute("BEGIN TRANSACTION")
connection.execute("COMMIT")
如果不使用事务, 批量添加数据非常缓慢
数据对比:
两种方式, 事务耗时差别不大
count = 100000
智能commit即时提交耗时: 0.621
自动commit耗时: 0.601
智能commit即时提交耗时: 0.588
自动commit耗时: 0.581
智能commit即时提交耗时: 0.598
自动commit耗时: 0.588
智能commit即时提交耗时: 0.589
自动commit耗时: 0.602
智能commit即时提交耗时: 0.588
自动commit耗时: 0.622
'''
import sys
import time
class Elapse_time(object):
'''耗时统计工具'''
def __init__(self, prompt=''):
self.prompt = prompt
self.start = time.time()
def __del__(self):
print('%s耗时: %.3f' % (self.prompt, time.time() - self.start))
CElapseTime = Elapse_time
import sqlite3
# -------------------------------------------------------------------------------
# 测试
#
filename = 'e:/temp/a.db'
def prepare(isolation_level = ''):
connection = sqlite3.connect(filename, isolation_level = isolation_level)
connection.execute("create table IF NOT EXISTS people (num, age)")
connection.execute('delete from people')
connection.commit()
return connection, connection.cursor()
def db_insert_values(cursor, count):
num = 1
age = 2 * num
while num <= count:
cursor.execute("insert into people values (?, ?)", (num, age))
num += 1
age = 2 * num
def study_case1_intelligent_commit(count):
'''
在智能commit状态下, 不能和cur.execute("COMMIT")共用
'''
connection, cursor = prepare()
elapse_time = Elapse_time(' 智能commit')
db_insert_values(cursor, count)
#cursor.execute("COMMIT") #产生异常
cursor.execute("select count(*) from people")
print (cursor.fetchone())
def study_case2_autocommit(count):
connection, cursor = prepare(isolation_level = None)
elapse_time = Elapse_time(' 自动commit')
db_insert_values(cursor, count)
cursor.execute("select count(*) from people")
print (cursor.fetchone())
def study_case3_intelligent_commit_manual(count):
connection, cursor = prepare()
elapse_time = Elapse_time(' 智能commit即时提交')
db_insert_values(cursor, count)
connection.commit()
cursor.execute("select count(*) from people")
print (cursor.fetchone())
def study_case4_autocommit_transaction(count):
connection, cursor = prepare(isolation_level = None)
elapse_time = Elapse_time(' 自动commit')
connection.execute("BEGIN TRANSACTION;") # 关键点
db_insert_values(cursor, count)
connection.execute("COMMIT;") #关键点
cursor.execute("select count(*) from people;")
print (cursor.fetchone())
if __name__ == '__main__':
count = 10000
prepare()
for i in range(5):
#study_case1_intelligent_commit(count) #不提交数据
#study_case2_autocommit(count) #非常缓慢
study_case3_intelligent_commit_manual(count)
study_case4_autocommit_transaction(count)
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希望本文所述对大家Python程序设计有所帮助。