You have to put your ForeignKeyConstraint in the __table_args__ for the PhoneNumber class - see http://docs.sqlalchemy.org/en/rel_0_8/orm/extensions/declarative.html#table-configuration for details. Something like:
class PhoneNumber(db.Model): __tablename__ = 'phonenumbers' phone_number = db.Column(db.Numeric(precision=4, scale=0), primary_key=True) exchange_exchange = db.Column(db.Integer, primary_key=True) exchange_area_code_pk = db.Column(db.Integer, primary_key=True) __table_args__ = (db.ForeignKeyConstraint( ['exchange_exchange', 'exchange_area_code_pk'], ['exchange.exchange', 'exchange.area_code_pk'], ), ) Simon On 7 Mar 2013, at 23:49, Randall Degges <rdeg...@gmail.com> wrote: > Hi Lloyd, > > Thank you! I believe this is what I was trying to figure out, although I am > having further issues now. Here's a recent pastie with my improved models, > along with the errors I'm now having, http://pastie.org/6417080 > > What I've done (as you can probably see) is I've used the > ForeignKeyConstraint on my PhoneNumber table, to ensure that I'm able to link > to my exchanges table properly. Unfortunately, this looks like it is not > being picked up by SQLAlchemy, since it's complaining that I have no Foreign > Keys for that table. > > Also, just for reference, I've totally wiped / recreated my DBs to test this, > so I'm sure it isn't a result of migrations or anything like that. > > If I run \d phonenumbers inside of psql, I get the following output > (http://pastie.org/6417088), thought that might also be of help. > > Thank you all for your help so far, I can't wait to get this working! > > Best, > > -Randall > > > On Thu, Mar 7, 2013 at 5:41 AM, Lloyd Kvam <goo...@venix.com> wrote: > While primary_key is specified twice, once for each column, there is only ONE > primary key which is a composite. > > You need to use ForeignKeyConstraint at the Table level to specify a > composite foreign key. > > You need to provide two lists, the local table columns, and the corresponding > foreign table columns. > Now you know what to search for if you need more information. > > from the schema definition language docs > It’s important to note that the ForeignKeyConstraint is the only way to > define a composite foreign key. While we could also have placed individual > ForeignKey objects on both theinvoice_item.invoice_id and > invoice_item.ref_num columns, SQLAlchemy would not be aware that these two > values should be paired together - it would be two individual foreign key > constraints instead of a single composite foreign key referencing two columns. > > > On Wednesday, March 6, 2013 9:00:56 PM UTC-5, Randall Degges wrote: > Hi Mike, > > Sorry about that, I actually had a typo there. I've got a correct code sample > available here > http://stackoverflow.com/questions/15260842/how-can-i-build-a-foreignkey-to-a-table-which-has-multiple-primary-keys > (just posted it). > > Thank you, > > -Randall > > > On Wed, Mar 6, 2013 at 5:54 PM, Michael Bayer <mik...@zzzcomputing.com> wrote: > a database table can only have one primary key (hence "primary"), but that > key can contain more than one column (a "composite" primary key). > > the model you have here is a little unclear, did you mean for the primary key > of Exchange to be "exchange" , and the primary key of PhoneNumber to be the > composite of "exchange" and "phone number" ? that would be my guess as to > what you're looking for. > > > > On Mar 6, 2013, at 6:05 PM, Randall Degges <rde...@gmail.com> wrote: > >> Hi all, >> >> I'm having a lot of trouble figuring out how to properly build my ForeignKey >> column for a table I'm defining. I've outlined my models here: >> http://pastie.org/6407419# (and put a comment next to the problematic line >> in my PhoneNumber model). >> >> Here's what's happening: >> >> My Exchange table has two primary keys. This is required for my use case. >> >> The PhoneNumber table I'm trying to define needs a ForeignKey to the >> Exchange table, but since the Exchange table has two primary keys, I can't >> figure out how to make the relationship work. >> >> Any guidance would be appreciated. Thank you. >> >> -- >> 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+...@googlegroups.com. >> >> To post to this group, send email to sqlal...@googlegroups.com. >> >> Visit this group at http://groups.google.com/group/sqlalchemy?hl=en. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > > -- > 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+...@googlegroups.com. > > To post to this group, send email to sqlal...@googlegroups.com. > > Visit this group at http://groups.google.com/group/sqlalchemy?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > -- > Randall Degges > http://rdegges.com/ > > -- > You received this message because you are subscribed to a topic in the Google > Groups "sqlalchemy" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/sqlalchemy/L3Z8yDiFa7g/unsubscribe?hl=en. > To unsubscribe from this group and all its topics, 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?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > -- > Randall Degges > http://rdegges.com/ > > -- > 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?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. 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