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SQLAlchemy ER schema in python 3

Does anyone know a way to generate ER diagram from SQLAlchemy models in python 3. I found sqlalchemy_schemadisplay which is python 2 because of pydot and ERAlchemy which is also python 2 only.

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You can try eralchemistry .

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()

Then the model shows it.



enter image description here

Those modules that I used:

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


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SQLAlchemy_SchemaDisplay works for me too.

On Windows, I installed Graphviz and these requirements via pip :



  • pydot
  • SQLAlchemy
  • sqlalchemy_schemadisplay
  • Graphviz

Then I added the Grapviz binary (bin) folder to the path and ran the code from the example at https://github.com/sqlalchemy/sqlalchemy/wiki/SchemaDisplay

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