Python SQLAlchemy

Author: ityard

day-086/__init__.py

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+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy import Column, Integer, String
+from sqlalchemy.orm import sessionmaker
+
+# 相对路径
+engine = create_engine('sqlite:///foo.db', echo=True)
+
+# 绝对路径
+# engine = create_engine('sqlite:///C:\\Users\\admin\\Desktop\\db\\foo.db')
+# engine = create_engine(r'sqlite:///C:\Users\admin\Desktop\db\foo.db')
+
+# 内存数据库
+# engine = create_engine('sqlite://', echo=True)
+# conn = engine.connect()
+
+# 映射基类
+Base = declarative_base()
+
+# 具体映射类
+class SysUser(Base):
+    # 指定映射表名
+    __tablename__ = 'sys_user'
+
+    # id 设置为主键
+    id = Column(Integer, primary_key=True)
+    # 指定 name 映射到 name 字段
+    name = Column(String(30))
+    password = Column(String(32))
+
+# 创建表
+# Base.metadata.create_all(engine)
+Session = sessionmaker(bind=engine)
+# 创建 Session 类实例
+session = Session()
+
+# 新增
+# su = SysUser(id=1, name='Jhon', password='123456')
+# 保存
+# session.add(su)
+# 提交
+# session.commit()
+# 关闭
+# session.close()
+
+# 查询
+# u = session.query(SysUser).filter(SysUser.id==1).one()
+# session.query(SysUser).filter(SysUser.id==1).all()
+# print('name-->',u.name)
+# session.close()
+
+# 修改
+# u = session.query(SysUser).filter(SysUser.id==1).one()
+# print('修改前名字-->', u.name)
+# u.name = 'James'
+# session.commit()
+# print('修改后名字-->', u.name)
+# session.close()
+
+# 删除
+u = session.query(SysUser).filter(SysUser.id==1).one()
+session.delete(u)
+session.commit()
+session.close()