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【DM版本】:dm8
【操作系统】：kylin
【CPU】:arm
【问题描述】*：Pythom sqlalchemy框架通过orm的方式插入一条数据，然后orm对象上补充的自增id为0，请问是包有问题还是我的用法问题呢？或者有没有其他方式可以获取到插入数据的自增id？辛苦老师们帮忙看看

Python环境
python版本：3.7.0
dmPython：2.3
sqlalchemy-dm：1.1.10

表定义为：

CREATE TABLE IF NOT EXISTS mytable (
    primary_id  bigint        PRIMARY KEY IDENTITY(1,1),
    uname       varchar(64)   NULL DEFAULT NULL
);

Python脚本:

from utils import get_session
from sqlalchemy import Table, MetaData, Column, INTEGER, VARCHAR
from sqlalchemy.orm import mapper

class Mytable:
    def __init__(self, primary_id=None, uname=None):
        self.primary_id = primary_id
        self.uname = uname

mytable = Table(
    'mytable', MetaData(),
    Column('primary_id', INTEGER, primary_key=True, autoincrement=True),
    Column('uname', VARCHAR(64), nullable=True),
)

mapper(Mytable, mytable)


session = get_session()
po = Mytable(uname = "AAA")
session.add(po)
print(po.__dict__)
# 输出为：{'_sa_instance_state': <sqlalchemy.orm.state.InstanceState object at 0xfffe8b8f6690>, 'primary_id': None, 'uname': 'AAA'}
session.flush()
print('after flush', po.__dict__)
# 输出为：after flush {'_sa_instance_state': <sqlalchemy.orm.state.InstanceState object at 0xfffe8b8f6690>, 'primary_id': 0, 'uname': 'AAA'}
session.commit()
print('after commit', po.__dict__)
# 输出为：after commit {'_sa_instance_state': <sqlalchemy.orm.state.InstanceState object at 0xfffe8b8f6690>}
session.close();