sqlalchemy.exc.ArgumentError about superset HOT 1 OPEN

class Dashboard(AuditMixinNullable, ImportExportMixin, Model):
    """The dashboard object!"""

    __tablename__ = "dashboards"
    id = Column(Integer, primary_key=True)
    dashboard_title = Column(String(500))
    position_json = Column(utils.MediumText())
    description = Column(Text)
    css = Column(utils.MediumText())
    certified_by = Column(Text)
    certification_details = Column(Text)
    json_metadata = Column(utils.MediumText())
    slug = Column(String(255), unique=True)
    slices: list[Slice] = relationship(
        Slice, secondary=dashboard_slices, backref="dashboards"
    )
    owners = relationship(
        security_manager.user_model,
        secondary=dashboard_user,
        passive_deletes=True,
    )
    tags = relationship(
        "Tag",
        overlaps="objects,tag,tags",
        secondary="tagged_object",
        primaryjoin="and_(Dashboard.id == TaggedObject.object_id, "
        "TaggedObject.object_type == 'dashboard')",
        secondaryjoin="TaggedObject.tag_id == Tag.id",
        viewonly=True,  # cascading deletion already handled by superset.tags.models.ObjectUpdater.after_delete
    )
    published = Column(Boolean, default=False)
    is_managed_externally = Column(Boolean, nullable=False, default=False)
    external_url = Column(Text, nullable=True)
    roles = relationship(security_manager.role_model, secondary=DashboardRoles)
    embedded = relationship(
        "EmbeddedDashboard",
        back_populates="dashboard",
        cascade="all, delete-orphan",
    )
    export_fields = [
        "dashboard_title",
        "position_json",
        "json_metadata",
        "description",
        "css",
        "slug",
        "certified_by",
        "certification_details",
        "published",
    ]
    extra_import_fields = ["is_managed_externally", "external_url"]

    @property
    def changed_by_name(self) -> str:
        if not self.changed_by:
            return ""
        return str(self.changed_by)