python - 在 SQLAlchemy 中获取表名

Question

from sqlalchemy import create_engine

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column,Integer,String
from sqlalchemy.orm import sessionmaker

engine = create_engine('mysql://we0:go@wecom/javadb', convert_unicode=True, echo=False)
try:
   engine.execute("use javadb")
   engine.connect()
   print 'connected'
except:
   print 'error'

Base = declarative_base()

Session = sessionmaker(bind=engine)

session = Session()

print engine.table_names()
print Base.metadata.tables
#print Base.metadata.reflect(engine)
class MontEmp(Base):
    __table__ = Base.metadata.tables['MONTGOMERY_EMPLOYEE']

for item in session.query(MontEmp.id):
        print item

我试图从现有数据库中获取表名并查询它，但是当我尝试通过 Base.metadata.tables['MONTGOMERY_EMPLOYEE'] 访问该表时出现错误，我收到关键错误。

当我打印 Base.metadata.tables 时，它是空的，但当我打印 engine.table_names() 时，它列出了所有表。

问题:-

为什么 Base.metadata.tables['MONTGOMERY_EMPLOYEE'] 是空的？

Answer 1

我遇到了同样的问题，我就是这样解决的。

from sqlalchemy.schema import MetaData
from sqlalchemy import create_engine

engine = create_engine(config.DATABASE_URL)
meta = MetaData()
meta.reflect(bind=engine)

meta.tables.keys()   <== this is what we were looking for