使用Flask在一对多SQLAlchemy数据库中出错

时间:2017-01-31 13:26:18

标签: python postgresql flask sqlalchemy

我目前正在尝试将项目插入我的数据库。我正在使用SQLlite和SQLAlchemy与Flask,但似乎有一个问题。每当我尝试从cmd手动插入项目时,都会收到错误。

  

此会话的交易由于之前已被回滚   冲洗期间的异常。

我已在我的数据库中实现了一对多的关系,但似乎一直在搞乱。这是我的Python代码:

from flask import Flask, render_template, request, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_bootstrap import Bootstrap

main = Flask(__name__)
db = SQLAlchemy(main)
main.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://YYYYYYY:XXXXXXX@localhost/address'
main.config['SECRET_KEY'] = 'something-secret'
Bootstrap(main)


class Organisation(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(40), unique=True)
    number = db.Column(db.String(40), unique=True)
    employees = db.relationship('Person', backref='employer', lazy='dynamic')

    def __init__(self, title, email, number):
        self.title = title
        self.email = email
        self.number = number



class Person(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(60), unique=False)
    email = db.Column(db.String(40), unique=True)
    mobile = db.Column(db.String(40), unique=True)
    employer_id = db.Column(db.Integer, db.ForeignKey('organisation.id'))

    def __init__(self, name, email, mobile, employer_id):
        self.name = name
        self.email = email
        self.mobile = mobile
        self.employer_id = employer_id



@main.route('/', methods=['GET'])
def index():
    result = Person.query.all()
    org_result = Organisation.query.all()
    return render_template("index.html", result=result, org_result=org_result)


@main.route('/additems', methods=['GET'])
def additems():
    return render_template('add.html')


@main.route('/add', methods=['GET', 'POST'])
def add():
    person = Person(request.form['name'], request.form['email'], request.form['mobile'])
    db.session.add(person)
    db.session.commit()


if __name__ == "__main__":
    main.run(debug=True)

如果我必须诚实,我认为我的问题出在 init 函数中。我试过用几种方法来改变它们:

1.将员工添加为self.employees =员工并直接尝试输入组织:  organisation_one=Organisation(title="XX",email="xx@mail.com",number="3838",employees=person_one)但是在我提交person_one

之前,它又回击了一个错误

2.我尝试在Person __ init __ 文件中引用 employer_id ,当我尝试添加组织ID时,我发现错误"可以&# 39; t适应类型"。

我对一对多数据库模型做错了什么?有人可以帮助我吗?

1 个答案:

答案 0 :(得分:1)

您的数据库模型需要__tablename__这样的属性:这告诉它实际的表名在数据库中是什么。否则SQLAlchemy不知道如何为你编写SQL。

class Organisation(db.Model):
    __tablename__ = 'organisation'
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(40), unique=True)
    number = db.Column(db.String(40), unique=True)
    employees = db.relationship('Person', backref='employer', lazy='dynamic')

    def __init__(self, title, email, number):
        self.title = title
        self.email = email
        self.number = number

您还必须在backref中为您的Person模型引用此表名:

db.ForeignKey('organisation.id'))  # assuming "organisation" is the table name

此外,您的/add路线不完整,会导致错误:

@main.route('/add', methods=['GET', 'POST'])
def add():
    person = Person(request.form['name'], request.form['email'], request.form['mobile'])
    db.session.add(person)
    db.session.commit()
    # e.g. add some instruction here on what to do...
    flash('Person %s <%s>added!' % (request.form['name'], request.form['email']))
    return redirect(url_for('main.additems'))