Validating value is unique

Hi

I have a user schema with an email field. The email is validated to be unique:

class UserSchema(ma.Schema):
    def validate_email(value):
        return User.query.filter(User.email == value).first() is None

    username = ma.fields.String()
    email = ma.fields.Email(validate=validate_email)

This works great when creating users, but when updating a user with same email address it fails because there is already a user with same email address: the same user as the one being updated!

The validator unfortunately only has access to the email value so I can’t check if the user found is the same as the one being updated.

How do I best handle this?

[maximkulkin]

I would suggest moving such validation outside of schema:

class UserSchema(ma.Schema):
    username = ma.fields.String()
    email = ma.fields.Email()

def user_exists(email):
    return User.query.filter(User.email == email).first() is not None

def user_create(payload):
    user_data, _ = UserSchema(strict=True).load(payload)
    if user_exists(user_data['email']):
        return {'error': 'User with this email already exists'}, 422
    user = User(**user_data)
    user.save()

[kazitanvirahsan]

You can use another schema for update.