python 3中的SQLAlchemy ER图

Question

有没有人知道从python 3中的SQLAlchemy模型制作ER图的方法.我找到了sqlalchemy_schemadisplay,它是python 2,因为pydot和ERAlchemy只是python 2.

Answer 1

正如之前的答案中提到的，sqlalchemy_schemadisplay是一个非常简单的工具。以下是使用它的基本方法：

from sqlalchemy_schemadisplay import create_schema_graph
from sqlalchemy import MetaData

graph = create_schema_graph(metadata=MetaData('postgres://user:pwd@host/database'))
graph.write_png('my_erd.png')

Answer 2

你可以试试eralchemy.

import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import pandas as pd
from eralchemy import render_er

from sqlalchemy import (MetaData, Table, Column)    
metadata = MetaData()

# create your own model ....
users = Table('users', metadata,
    Column('user_id', Integer(), primary_key=True),
    Column('username', String(15), nullable=False, unique=True),
)    
orders = Table('orders', metadata,
    Column('order_id', Integer()),
    Column('user_id', ForeignKey('users.user_id')),
)
# add your own table ....

# Show ER model from here
filename = 'mymodel.png'
render_er(metadata, filename)
imgplot = plt.imshow(mpimg.imread(filename))
plt.rcParams["figure.figsize"] = (15,10)
plt.show()

然后它显示模型.

我使用的那些模块是:

Software Version
Python 3.4.5 64bit
IPython 5.1.0
OS Windows 10
sqlalchemy 1.1.5
eralchemy 1.1.0
matplotlib 2.0.0