实体联系图自动生成系统

关于pygraphviz的依赖

Code

apt install graphviz-dev

sudo pip install pygraphviz --install-option="--include-path=/usr/local/include/graphviz/" --install-option="--library-path=/usr/local/lib/graphviz"
# 在安装的时候指定graphviz的路径
在windows下要指定

json与实体之间的转换
json表示联系

pygraphviz 接受 dot ,改为 graphviz 应无变化

Code

![Alt Text](http://webtools.company_domain.net/graphviz/?
digraph G {
    aize ="4,4";
    main [shape=box];
    main -> parse [weight=8];
    parse -> execute;
    main -> init [style=dotted];
    main -> cleanup;
    execute -> { make_string; printf};
    init -> make_string;
    edge [color=red];
    main -> printf [style=bold,label="100 times"];
    make_string [label="make a string"];
    node [shape=box,style=filled,color=".7 .3 1.0"];
    execute -> compare;
  })

使用gunicorn部署flask项目

安装gunicorn

假设flask的app.p

python

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

在shell中输入

python

1 2	gunicorn -w 3 -b 127.0.0.1:5000 app:app #第一个为flask项目实例所在的包,第二个为app生成的flask项目

sqlalchemy 涉及到的知识点

sqlalchemy.ext.declarative.declarative_base

sqlalchemy.orm.relationship

引用到的包

python

from sqlalchemy import Table, Column, Integer, ForeignKey
from sqlalchemy.orm import relationship
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

一对多

父节点和子节点

python

class Parent(Base):
    __tablename__ = 'parent'
    id = Column(Integer, primary_key=True)
    children = relationship("Child")

class Child(Base):
    __tablename__ = 'child'
    id = Column(Integer, primary_key=True)
    parent_id = Column(Integer, ForeignKey('parent.id'))

metadata型,declarative型

column属性:

数据类型:

关系

json to base

属性:

json

1	{"tablename":"base","columns":"[{"name":"xxx":}]","relationships":"xxx"}

gua