python - 如何自动将数据库反射(reflect)到 sqlalchemy 声明性？

Question

sqlautocode - 存在多对多关系问题

sqlsoup - 不支持关系

elixir - 笔记自动生成

还有什么我可以尝试的吗？

Answer 1

理论上，sqlalchemy 中的反射应该适合您。在这种情况下，我使用的是带有两个表的 mssql 数据库，这两个表具有简单的多对一关系:

带有字段的“测试”:

• 身份证
• 测试名称
• author_id(Users 表的外键，Users.id 字段)

带有字段的“用户”:

• 身份证
• 全名

所以以下应该反射(reflect)数据库:

from sqlalchemy import *
from sqlalchemy.orm import create_session
from sqlalchemy.schema import Table, MetaData
from sqlalchemy.ext.declarative import declarative_base

#Create and engine and get the metadata
Base = declarative_base()
engine = create_engine('put your database connect string here')
metadata = MetaData(bind=engine)

#Reflect each database table we need to use, using metadata
class Tests(Base):
    __table__ = Table('Tests', metadata, autoload=True)

class Users(Base):
    __table__ = Table('Users', metadata, autoload=True)

#Create a session to use the tables    
session = create_session(bind=engine)

#Here I will just query some data using my foreign key relation,  as you would
#normally do if you had created a declarative data mode.
#Note that not all test records have an author so I need to accomodate for Null records
testlist = session.query(Tests).all()    

for test in testlist:
    testauthor = session.query(Users).filter_by(id=test.author_id).first()  
    if not testauthor:
        print "Test Name: {}, No author recorded".format(test.testname)
    else:
        print "Test Name: {}, Test Author: {}".format(test.testname, testauthor.fullname)

所以这似乎适用于表关系。尽管您仍然没有详细说明您正在尝试做什么。