python操作mysql③python操作mysql的orm工具sqlaichemy安装配置和使用

//docs.sqlalchemy.org/en/rel_1_1/orm/index.html 安装 D:\software\source_tar>pip install SQLALchemy 检测是否安装成功 D:\software\source_tar>python Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import sqlalchemy mysql的orm库SQLALchemy的操作 #coding:utf-8 from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, DateTime, Boolean from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker ‘‘‘ id int primary key auto_increment, title varchar(200) not null, content varchar(2000) not null, tpes varchar(10) not null, image varchar(300) null, author varchar(20) null, view_count int default 0, created_at datetime null, is_valid smallint default 1 ‘‘‘ # 创建对象的基类 Base = declarative_base() # 初始化数据库连接，注意要接上charset=utf8否则中文无法支持 engine = create_engine("mysql://root:@localhost/news?charset=utf8") # 创建DBSession类型 DBSession = sessionmaker(bind=engine) # 定义News对象 class News(Base): __tablename__ = ‘news‘ id = Column(Integer, primary_key=True) title = Column(String(200), nullable=False) content = Column(String(2000), nullable=False) types = Column(String(10), nullable=False) image = Column(String(300),) author = Column(String(20),) view_count = Column(Integer) created_at = Column(DateTime) is_valid = Column(Boolean) ‘‘‘ # 简单测试 # 如果表不存在就创建表 Base.metadata.create_all(engine) # 创建session对象: session = DBSession() # 创建新User对象，新增一条测试数据 news01 = News(title=‘标题1‘, content = ‘content01‘, types = ‘baidu‘, image = ‘/static/img/01.jpg‘, author = ‘jack‘, view_count = 3) # 添加到session: session.add(news01) # 提交即保存到数据库: session.commit() # 关闭session: session.close() ‘‘‘ # orm的测试类 class OrmTest(object): # 初始化创建session def __init__(self): self.session = DBSession() # 添加数据 def add_one(self): new_obj = News( title = ‘标题20180202‘, content = ‘内容20180202‘, types = ‘百家‘ ) self.session.add(new_obj) self.session.commit() return new_obj # 添加多条数据 def add_more(self): add_list = [] for i in range(10): new_obj = News(title=‘标题%s‘%str(i),content=‘内容%s‘%str(i),types=‘百家%s‘%str(i)) self.session.add(new_obj) add_list.append(new_obj) self.session.commit() return add_list # 删除数据 def delete_data(self): data = self.session.query(News).get(51) self.session.delete(data) self.session.commit() # 修改单条数据 def update_one(self, _id): obj = self.session.query(News).get(_id) if obj: obj.is_valid = 0 self.session.add(obj) self.session.commit() return True return False # 修改多条数据 def update_data(self): # filter_by的使用方法 # data_list = self.session.query(News).filter_by(is_valid = 0) # filter的使用方法 data_list = self.session.query(News).filter(News.id > 45) for data in data_list: print(data.title) data.is_valid = 1 self.session.add(data) self.session.commit() # 获取一条数据 def get_one(self): return self.session.query(News).get(1) # 获取多条数据 def get_more(self): return self.session.query(News).filter_by(is_valid = 1) def main(): obj = OrmTest() # rst = obj.add_one() # print(‘id:%s, title:%s,content:%s,types = %s‘ % (rst.id,rst.title,rst.content,rst.types)) # 添加多条数据 # rst = obj.add_more() # for _new in rst: # print(‘id:{0},title{1},content:{2}‘.format(_new.id,_new.title,_new.content)) # 测试删除 # obj.delete_data() # 修改单条数据 # print(obj.update_one(50)) # 修改多条数据 obj.update_data() # 测试获取一条数据的函数 # rst = obj.get_one() # print(rst.title) # 获取多条数据 # rst = obj.get_more() # for _news in rst: # print(‘news id: %s, title:%s, content:%s‘ % (_news.id,_news.title,_news.content)) if __name__ == "__main__": main()

 

python操作mysql③python操作mysql的orm工具sqlaichemy安装配置和使用

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