I'm having fun trying to visualize this in my head, but I have 4 tables, 3 are basic relations, but the 4th table links to table 2.
Should I take the 4th table and have a relation join with all 3 tables or can I just relate to table 2 and have table 2 relations do the rest? Tables 1-3 are basic equipment relationships: 1 - manufacturer 2 - model (foreignkey manufaturer.id) 3 - sources (foreignkey model.id) (sources = inputs available) manufacturers_table = Table(u'manufacturer', metadata, Column(u'id', Integer, primary_key=True), Column(u'name', String(50)) ) models_table = Table(u'model', metadata, Column(u'id', Integer, primary_key=True), Column(u'manufacturer_id', Integer, ForeignKey(u'manufacturer.id')), Column(u'name', String(50)) ) sources_table = Table(u'source', metadata, Column(u'id', Integer, primary_key=True), Column(u'model_id', Integer, ForeignKey(u'model.id')), Column(u'label', String(20)), ) The 4th table keeps track of equipment installed at the premise. 4 - projector (foreignkey model.id) projector_table = Table(u'projector', metadata, Column(u'id', Integer, primary_key=True), Column(u'model_id', Integer, ForeignKey(u'model.id')), ) Tables 1-3 will be updated separately, the projector table will only join with the other tables for reading. The question(s) would be on the joins: 1 ) Use projector table with join to model table (and model table will take care of the joins with manufacturer and sources) 2) Add table 1 and 3 to projector: projector_table = Table(u'projector', metadata, Column(u'id', Integer, primary_key=True), Column(u'manufacturer_id', Integer, ForeignKey(u'manufacture.id')), Column(u'model_id', Integer, ForeignKey(u'model.id')), Column(u'sources_id', Integer, ForeighKey(u'sources.id')) ) Hope I'm making myself understood - databases with multiple relations are not my strong suit. -- 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 http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.