sqlalchemy 的 ORM 与 Core 混合方式使用示例

1. 绑定数据库

from sqlalchemy import create_engine

engine = create_engine('sqlite:///:memory:',echo = True)

2. 建立会话

from sqlalchemy.orm import Session

session = Session(engine)

3. 元数据

from sqlalchemy import MetaData

metadata = MetaData(engine)

4. 定义表

from sqlalchemy import Table, Column, Integer, String, ForeignKey

users_table = Table('users', metadata,
Column('id', Integer, primary_key = True),
Column('name', String),
Column('fullname', String),
Column('password', String)
)

5. 创建表

# metadata.create_all() # 方式一
users_table.create() # 方式二

6. 定义类

class User(object):
def __init__(self,name,fullname,password):
self.name = name
self.fullname = fullname
self.password = password

def __repr__(self):
return "<User('%s','%s','%s')>" % (self.name, self.fullname, self.password)

7. 映射类、表

from sqlalchemy.orm import mapper

mapper(User, users_table)

8. 然后，就可以使用会话对数据库进行操作

session.add(User('ed','Ed Jones','edspassword'))
session.commit()

9. 完整代码

# 绑定数据库
from sqlalchemy import create_engine
engine = create_engine('sqlite:///:memory:',echo = True)

# 建立会话
from sqlalchemy.orm import Session
session = Session(engine)

# 元数据
from sqlalchemy import MetaData
metadata = MetaData(engine)

# 定义表
from sqlalchemy import Table, Column, Integer, String, ForeignKey
users_table = Table('users', metadata,
Column('id', Integer, primary_key = True),
Column('name', String),
Column('fullname', String),
Column('password', String)
)

# 创建表
# metadata.create_all() # 方式一
users_table.create() # 方式二

# 定义类
class User(object):
def __init__(self,name,fullname,password):
self.name = name
self.fullname = fullname
self.password = password

def __repr__(self):
return "<User('%s','%s','%s')>" % (self.name, self.fullname, self.password)

# 映射类、表
from sqlalchemy.orm import mapper
mapper(User, users_table)

# 然后，就可以使用会话对数据库进行操作
session.add(User('ed','Ed Jones','edspassword'))
session.commit()