Flask WTForms自定义验证程序不起作用

Question

此自定义验证程序应检查2个数据库，以查看表单中输入的值是否等于training_name和date列中的值。但是，如果我输入数据库中存在的重复记录，则不会引发任何错误。请指教

class add_training_form(FlaskForm): #All fields are required
    training_course = SelectField('Training Course', choices=[], validators=[DataRequired()]) #The choices will be assigned in route
    training_provider = SelectField('Training Provider', choices=[], validators=[DataRequired()])
    date = DateField('Date of Training', validators=[DataRequired()])
    cpd = IntegerField('CPD hours',validators=[DataRequired(message='Invalid input')] )
    certificate = FileField('Certificate', validators=[FileRequired(),FileAllowed(['jpg','png','pdf'])])#For certificate

    submit = SubmitField('Submit')

    def validate_duplicate(self, training_course, date):
        training = Training.query.filter_by(training_name=training_course.data,date=date.data).first()
        mv = ManagerVerification.query.filter_by(training_name=training_course.data,date=date.data).first()
        if training or mv:
            raise ValidationError('This is a duplicate training record')

Answer 1

在Wtforms中编写文档，如果您想创建自定义验证器，则需要在FlaskForm类内创建一个函数，其当前名称为'validate_ + {您的字段名}'，并且FlaskWtf将通过整个表单和字段，我认为这段代码会为您工作

class add_training_form(FlaskForm): #All fields are required
    training_course = SelectField('Training Course', choices=[], validators=[DataRequired()]) #The choices will be assigned in route
    training_provider = SelectField('Training Provider', choices=[], validators=[DataRequired()])
    date = DateField('Date of Training', validators=[DataRequired()])
    cpd = IntegerField('CPD hours',validators=[DataRequired(message='Invalid input')] )
    certificate = FileField('Certificate', validators=[FileRequired(),FileAllowed(['jpg','png','pdf'])])#For certificate

    submit = SubmitField('Submit')

    def validate_training_course(form, training_course):
        training = Training.query.filter_by(training_name=training_course.data,date=form.date.data).first()
        mv = ManagerVerification.query.filter_by(training_name=training_course.data,date=form.date.data).first()
        if training or mv:
            raise ValidationError('This is a duplicate training record')