Python 如何在flask中验证WTF窗体中的两个validate_字段

这里我有两个验证函数，用于检查它是否已经存在于数据库中。但我想检查两者是否作为一个组合在DB中可用，而不是其中一个或另一个

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例如：如果我添加release=50和product PS1，下一次尝试如果我尝试release=50和product as XBOX1，它应该允许我，除非我再次尝试将相同的产品添加到同一版本。

self参数是允许您访问任何表单字段值的表单实例

from flask_wtf import FlaskForm
from flask_wtf.file import FileField, FileAllowed
from flask_login import current_user
from wtforms import StringField, PasswordField, SubmitField, BooleanField, SelectField,IntegerField
from wtforms.validators import DataRequired, Length, Email, EqualTo, ValidationError
from gsapp.models import User, Date

YesNo_CHOICES=[('1', 'Yes'), ('2', 'No')]

class ReleaseForm(FlaskForm):
    release = StringField('Release', validators=[
                           DataRequired(), Length(min=2, max=3)])
    product = StringField('Product', validators=[DataRequired()])
    yesno = SelectField(label='Yes/No', choices=YesNo_CHOICES)
    duration = IntegerField(label='Duration',validators=[DataRequired()])
    pmfreq = StringField('PMF Required', validators=[DataRequired()])
    compreq = StringField('Components Required', validators=[DataRequired()])
    cestory = StringField('CE Story', validators=[DataRequired()])
    submit = SubmitField('Submit')


    def validate_product(self,product):
        date = Date.query.filter_by(product=product.data).all()
        if date:
            raise ValidationError(
                "You've already have added for the selected, Thank-you!")

    def validate_release(self,release):
        date = Date.query.filter_by(release=release.data).all()
        if date:
            raise ValidationError(
                "You've already have added for the selected, Thank-you!")

def validate_product(self,product):
    release_data = self.release.data
    date = Date.query.filter_by(product=product.data, release=release_data).all()
    if date:
        raise ValidationError(
            "You've already have added for the selected, Thank-you!")

def validate_release(self,release):
    product_data = self.product.data
    date = Date.query.filter_by(release=release.data, product=product_data).all()
    if date:
        raise ValidationError(
            "You've already have added for the selected, Thank-you!")