I have the following Table model representing a timeline. class TimeRange(Base):
__tablename__ = "time_line" record_id = Column(Integer, primary_key=True) level = Column(String, nullable=False) # e.g. "Point", "Range" content = Column(String, nullable=False) language_marker = Column(String) # this one column is optional and needs to be queried immediate_parent_id = Column(Integer, ForeignKey('time_line.record_id')) child_timelines = relationship('TimeRange', backref=backref( 'parent_timeline', remote_side=[record_id])) The language_marker Column is the one that needs to be queried in a recursive manner. Not all records have such an attribute, and the business logic is: along the hierarchy lineage from the root down to the child timelines, at least one level of the TimeRange instance carries such an attribute, and the one in the lowest level should be returned. This works a little like cascading style sheet, where if the TimeRange object itself doesn't have such an attribute, just look further up one level above, util found one, and the latest defined style wins. What is the technical direction I should look into to implement such queries? I'm using SQLAlchemy and the backend is SQLite. Thanks. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.