问题描述
我不明白。我正在尝试使用以下内容在 MS sql Server 2012 中启动一个全新的表:
In sql Server:
TABLE [dbo].[Inventory](
[Index_No] [bigint] IDENTITY(1,1) NOT NULL,[Part_No] [varchar(150)] NOT NULL,[Shelf] [int] NOT NULL,[Bin] [int] NOT NULL,PRIMARY KEY CLUSTERED
(
[Index_No] ASC
)
UNIQUE NONCLUSTERED
(
[Part_No] ASC
)
GO
注意:这是一张全新的桌子!里面根本没有数据
接下来,这是Database.py文件:
import pymssql
from sqlalchemy import create_engine,Table,MetaData,select,Column,Integer,Float,String,text,func,desc,and_,or_,Date,insert
from marshmallow_sqlalchemy import sqlAlchemyAutoSchema
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
USERNAME = "name"
PSSWD = "none_of_your_business"
SERVERNAME = "MYSERVER"
INSTANCENAME = "\sqlSERVER2012"
DB = "Inventory"
engine = create_engine(f"mssql+pymssql://{USERNAME}:{PSSWD}@{SERVERNAME}{INSTANCENAME}/{DB}")
class Inventory(Base):
__tablename__ = "Inventory"
Index_No = Column('Index_No',primary_key=True,autoincrement=True)
Part_No = Column("Part_No",unique=True)
Shelf = Column("Shelf",Integer)
Bin = Column("Bin",Integer)
def __repr__(self):
return f'Drawing(Index_No={self.Index_No!r},Part_No={self.Part_No!r},Shelf={self.Shelf!r},' \
f'Bin={self.Bin!r})'
class InventorySchema(sqlAlchemyAutoSchema):
class Meta:
model = Inventory
load_instance = True
还要注意的是,我使用的是 sqlAlchemy 1.4.3,如果有帮助的话。
在 main.py 中
import Database as db
db.Base.Metadata.create_all(db.engine)
data_list = [{Part_No:123A,Shelf:1,Bin:5},{Part_No:456B,Bin:7},{Part_No:789C,Shelf:2,Bin:1}]
with db.Session(db.engine,future=True) as session:
try:
session.add_all(data_list) #<--- FAILS HERE AND THROWS AN EXCEPTION
session.commit()
except Exception as e:
session.rollback()
print(f"Error! {e!r}")
raise
finally:
session.close()
现在我在这个“类'builtins.dict'未映射”上搜索的内容,大多数解决方案都将我带到了我尝试过的marshmallow-sqlalchemy包,但我仍然得到相同的结果错误。所以我尝试将 Base.Metadata.create_all(engine) 从 Database.py 移动到 main.py。我还尝试在 Inventory 类中实现 init 函数,并调用 super().init,但它不起作用
这是怎么回事??为什么会失败,是否有更好的解决方案?
解决方法
尝试创建 Inventory 对象:
data_list = [
Inventory(Part_No='123A',Shelf=1,Bin=5),Inventory(Part_No='456B',Bin=7),Inventory(Part_No='789C',Shelf=2,Bin=1)
]