sqlalchemy-schemadisplay 2.0

sqlalchemy_schemadisplay

将SQLAlchemy数据库模型转换为图形。

有关此文档的先前版本，请参阅 SQLAlchemy维基。

用法

您至少需要SQLAlchemy和pydot以及graphviz。Graphviz-cairo强烈推荐以获得可接受的图像质量。如果可用PIL和图像查看器，则有一些函数可以自动显示图像。某些内容，特别是通过映射器从数据库中加载表列表以及反射索引，目前仅在PostgreSQL上工作。

这是数据库实体图生成的一个示例

from sqlalchemy import MetaData
from sqlalchemy_schemadisplay import create_schema_graph

# create the pydot graph object by autoloading all tables via a bound metadata object
graph = create_schema_graph(metadata=MetaData('postgres://user:pwd@host/database'),
   show_datatypes=False, # The image would get nasty big if we'd show the datatypes
   show_indexes=False, # ditto for indexes
   rankdir='LR', # From left to right (instead of top to bottom)
   concentrate=False # Don't try to join the relation lines together
)
graph.write_png('dbschema.png') # write out the file

以及从模型生成的UML类图

from myapp import model
from sqlalchemy_schemadisplay import create_uml_graph
from sqlalchemy.orm import class_mapper

# lets find all the mappers in our model
mappers = [model.__mapper__]
for attr in dir(model):
    if attr[0] == '_': continue
    try:
        cls = getattr(model, attr)
        mappers.append(cls.property.entity)
    except:
        pass

# pass them to the function and set some formatting options
graph = create_uml_graph(mappers,
    show_operations=False, # not necessary in this case
    show_multiplicity_one=False # some people like to see the ones, some don't
)
graph.write_png('schema.png') # write out the file

变更日志