Python更新数据库脚本两种方法及对比介绍

import MySQLdb
#主机名
HOST = '127.0.0.1'
#用户名
USER = "root"
#密码
PASSWD = "123456"
#数据库名
DB = "db_name"
# 打开数据库连接
db=MySQLdb.connect(HOST,USER,PASSWD,DB)
# 获取操作游标
cursor=db.cursor()
if __name__ == '__main__':
  if cursor:
    command_a = "update tables_one set status=5 where status=0"
    # 使用execute方法执行SQL语句
    cursor.execute(command_a)
    # 提交到数据库执行
    db.commit()
    command2 = "select field from tables_one where id =12"
    ret2 = cursor.execute(command2)
    # 获取所有记录列表
    ret2=cursor.fetchall()
    for item in ret2:
        command3 = "insert into tables_two(name) values (%s);" % (item[0])
        fin=cursor.execute(command3)
        db.commit()
    # 关闭数据库连接
    db.close()

# -*- coding:utf-8 -*-
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.sql import text
HOST = '127.0.0.1'
USER = "root"
PASSWD = "123456"
DB = "carrier_test"
CHARTSET = "utf8"
app = Flask(__name__,instance_relative_config = True)
#链接数据库路径
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://%s:%s@127.0.0.1:3306/%s?charset=%s' %(USER,PASSWD,DB,CHARTSET)
#如果设置成 True (默认情况)，Flask-SQLAlchemy 将会追踪对象的修改并且发送信号。这需要额外的内存， 如果不必要的可以禁用它。
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
#如果设置成 True，SQLAlchemy 将会记录所有 发到标准输出(stderr)的语句，这对调试很有帮助。
app.config['SQLALCHEMY_ECHO'] = False
# 数据库连接池的大小。默认是数据库引擎的默认值 （通常是 5）。
app.config['SQLALCHEMY_POOL_SIZE'] = 6
db = SQLAlchemy(app)
class Table_one(db.Model):
  __tablename__ = 'table_one'
  id = db.Column('id', db.Integer, primary_key=True, autoincrement=True)
  com_name = db.Column('com_name', db.String(30), nullable=False)
  com_about = db.Column('com_about', db.String(200), nullable=False)
  def __repr__(self):
    return '<table_one com_name %r>' % self.com_name
class Table_two(db.Model):
  __tablename__ = 'table_two'
  id = db.Column('id', db.Integer, primary_key=True, autoincrement=True)
  reason = db.Column('reason', db.String(128), nullable=True)
  create_time = db.Column('create_time', db.TIMESTAMP, server_default=text('now()'))
  status = db.Column('status', db.Integer, nullable=False, default=0)
  def __repr__(self):
    return '<table_two id %r>' % self.id
def db_commit_all(lists):
  try:
    db.session.add_all(lists)
    db.session.commit()
    return 'SUCCESS'
  except Exception,e:
    return 'Fail!!!'
def commits_to_three_judge():
  com_sta_obj = Table_one.query.filter_by(com_name='只是测试使用,不用关心表间关系').all()
  for ite in com_sta_obj:
    ship_obj = Table_two.query.filter_by(id=ite.id).first()
    if ship_obj:
      if int(ship_obj.status) == 2:
        ite.status = 0
        print db_commit_all([ite])
  print '表同步结束'
64 
if __name__=='__main__':
  #执行更新数据库函数
  commits_to_three_judge()