📅 最后修改于: 2020-11-27 07:42:43 🧑 作者: Mango
为了与数据库进行交互，我们需要获取其句柄。会话对象是数据库的句柄。会话类是使用sessionmaker()定义的-一种可配置的会话工厂方法，该方法绑定到之前创建的引擎对象。
from sqlalchemy.orm import sessionmaker
Session = sessionmaker(bind = engine)
然后使用其默认构造函数设置会话对象，如下所示：
session = Session()
下面列出了一些常见的会话类方法-
| Sr.No. | Method & Description |
|---|---|
| 1 |
begin() begins a transaction on this session |
| 2 |
add() places an object in the session. Its state is persisted in the database on next flush operation |
| 3 |
add_all() adds a collection of objects to the session |
| 4 |
commit() flushes all items and any transaction in progress |
| 5 |
delete() marks a transaction as deleted |
| 6 |
execute() executes a SQL expression |
| 7 |
expire() marks attributes of an instance as out of date |
| 8 |
flush() flushes all object changes to the database |
| 9 |
invalidate() closes the session using connection invalidation |
| 10 |
rollback() rolls back the current transaction in progress |
| 11 |
close() Closes current session by clearing all items and ending any transaction in progress |