使用flask sqlalchemy查询数据库中现有的mysql表

我有一个flask应用程序,使用flask slqalchemy查询mysql数据库

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:password@localhost/abc'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)

“abc”数据库中有一个表“users”,它已经填充了几百行。现在我需要导入这个现有的表,而不是首先用db.model定义它我该怎么叫桌子? 如果我这样做

from sqlalchemy import Table
USERS = Table('users', db.metadata,autoload=True, autoload_with=db.engine)

那我就不能像

USERS.query.filter_by(done=1).with_entities(USERS.name,USERS.country).paginate(page, 15, False)

它会产生一个错误

AttributeError: 'Table' object has no attribute 'query'

因为这是sqlchemy命令,而不是flask sqlchemy,所以我不完全理解这一点。

我必须像第一次创建表一样首先定义表用户:

class USERS(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.VARCHAR(500))
    country = db.Column(db.VARCHAR(50))

    def __init__(self, id, name, country):
        self.id = id
        self.name = name
        self.country = country

    def __repr__(self):
    return self.id

只有这样,我才能使用用户通过flask sqlalchemy查询数据库

如何在flask应用程序中使用flask sqlchemy访问现有的表用户?

from sqlalchemy import Table, Column, String, create_engine, MetaData from sqlalchemy.orm import sessionmaker engine = create_engine() metadata = MetaData() test_ = Table('test', metadata, Column('msg', String, primary_key=True), Column('msg_', String) ) Session = sessionmaker(bind=engine) session = Session() print(session.query(test_).filter_by(msg_ = "test").with_entities("msg","msg_").one()) # ('t', 'test')

from flask import Flask from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = "" db = SQLAlchemy(app) class test(db.Model): msg = db.Column(db.String, primary_key=True) msg_ = db.Column(db.String) def __init__(self, msg, msg_): self.msg = msg self.msg_ = msg_ def __repr__(self): return "msg: {} msg_: {}".format(self.msg,self.msg_) result = test.query.filter_by(msg_="test").one() print(result) print(result.msg,result.msg_) ''' msg: t msg_: test t test '''