我有两个类模型，它们转换为两个MySQL数据库表。一个是employees，另一个是projects。他们有一对多的关系，即一个项目可以有几个员工。在我的网络表单中注册员工时，我有一个包含项目的下拉列表。表employees具有引用projects表的外键，因此employees表具有Integer列（emp_project_id）作为来自{{的外键1}}表。从下拉列表中选择项目时如何保存ID？
projects这是class Employee(UserMixin, db.Model):
"""
Create Employee table
"""
# Ensures table will be named in plural and not in singular
# as in the name of the model
__tablename__ = 'employees'
id = db.Column(db.Integer, primary_key=True)
emp_number = db.Column(db.String(10), index=True, unique=True, nullable=False)
username = db.Column(db.String(60), index=True, unique=True)
email = db.Column(db.String(60), index=True, unique=True, nullable=False)
emp_name = db.Column(db.String(100), index=True)
password_hash = db.Column(db.String(128))
emp_project_id = db.Column(db.Integer, db.ForeignKey('projects.id'), nullable=False)
表
projects如果可能的话，请告诉我我可以通过的资源，因为我没有在他们的文档中找到解决方案。
以下是class Project(db.Model):
"""
Create a Project table
"""
__tablename__ = 'projects'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(60), unique=True, nullable=False)
description = db.Column(db.String(200), nullable=False)
pro_subprojects = db.relationship('Subproject', backref='sp_project',
lazy='dynamic')
pro_employees = db.relationship('Employee', backref='emp_project',
lazy='dynamic')
创建表单
forms.py以下是我在class RegistrationForm(FlaskForm):
"""
Form for users to create new account
"""
project = QuerySelectField(query_factory=lambda: Project.query.all(),
get_label="name")
subproject = QuerySelectField(query_factory=lambda: Subproject.query.all(),
get_label="name")
emp_number = StringField('Employee Number', validators=[DataRequired()])
email = StringField('Email', validators=[DataRequired(), Email()])
username = StringField('Username', validators=[DataRequired()])
emp_name = StringField('Full Name', validators=[DataRequired()])
password = PasswordField('Password', validators=[
DataRequired(),
EqualTo('confirm_password')
])
confirm_password = PasswordField('Confirm Password')
submit = SubmitField('Register')
上添加的内容：
views.py但是当我尝试注册员工时，我收到了@auth.route('/register', methods=['GET', 'POST'])
def register():
"""
Handle requests to the /register route
Add an employee to the database through the registration form
"""
form = RegistrationForm()
if form.validate_on_submit():
employee = Employee(project=form.project.data,
subproject=form.subproject.data,
emp_number=form.emp_number.data,
email=form.email.data,
username=form.username.data,
emp_name=form.emp_name.data,
password=form.password.data)
# add employee to the database
db.session.add(employee)
db.session.commit()
flash('You have registered successfully. You can now log in.')
之类的错误。请帮助
答案 0 :(得分：0)
这是the documentation for QuerySelectedField中的内容：
data属性实际上将存储/保留ORM模型实例，而不是 ID。
现在我理解你的问题会改变你的观点：
@auth.route('/register', methods=['GET', 'POST'])
def register():
"""
Handle requests to the /register route
Add an employee to the database through the registration form
"""
form = RegistrationForm()
if form.validate_on_submit():
employee = Employee(
emp_number=form.emp_number.data,
email=form.email.data,
username=form.username.data,
emp_name=form.emp_name.data,
password=form.password.data)
project=form.project.data #an instance of Project Class
subproject=form.subproject.data #an instance of SubProject Class
project.pro_subproject.append(subproject)
project.pro_employee.append(employee)
# add employee to the database
db.session.add(employee)
db.session.add(subproject)
db.session.add(project)
db.session.commit()
flash('You have registered successfully. You can now log in.')
Here is an explanation of that :
一对多关系将外键放在子表上 引用父级。然后在。上指定 relationship（） parent，引用由表示的项集合 子：
这意味着在项目表中，字段pro_employees和pro_subproject是employee（n）和sub_project（n）的列表。