class ExtraData(db.Model):
    __tablename__ = "asset_extradata"
    id = db.Column(db.Integer, primary_key=True)
    table_name = db.Column(db.String(50))  # name of the table for which extra data needs to be added
    record_id = db.Column(db.Integer, sqla.ForeignKey('asset.id'))  #id of the record from the table for which extra data needs to be added
    field_name = db.Column(db.String(50))  #name of the field
    field_value = db.Column(db.String(100)) #value for the above field name