class Role(db.Model):    __tablename__='roles'    id = db.Column(db.Integer,primary_key=True)    name = db.Column(db.String(64),unique=True)    users = db.relationship('User',backref='role')    def __repr__(self):        return '
     
      '% self.nameclass User(db.Model):    __tablename__ = 'users'    id = db.Column(db.Integer, primary_key=True)    username = db.Column(db.String(64), unique=True,index=True)    role_id=db.Column(db.Integer,db.ForeignKey('role.id'))    def __repr__(self):        return '
      
       ' % self.username
      
     

设置SQLALCHEMY_TRACK_MODIFICATIONS 为True或False报错：FSADeprecationWarning：需要：提示给的839行，在前面几行的位置有这样的setdefault， 把None改为True;：

视图函数中操作数据库

@app.route('/', methods=['get', 'post'])def index1():    #name = None    form = NameForm()    if form.validate_on_submit():        user = User.query.filter_by(username=form.name.data).first()        if user is None:            user = User(username=form.name.data)            db.session.add(user)            session['known']=False        else:            session['known'] = True        session['name']=form.name.data        form.name.data=''        return redirect(url_for('index1'))    return render_template('index.html', name=session.get('name'), form=form, known=session.get('known',False))

 

# 集成python shelldef make_shell_context():    return dict(app=app, db=db, User=User, Role=Role)manager.add_command("shell", Shell(make_context=make_shell_context))

数据库迁移 

pip install flask-migrate

from flask_migrate import Migrate,MigrateCommand

# 数据库迁移migrate = Migrate(app,db)manager.add_command('db',MigrateCommand) # init命令创建迁移仓库 python flask_blog.py db init # 创建迁移脚本 python flask_blog.py db migrate -m 'initial migration' # 更新数据库 python flask_blog.py db upgrade