diff options
| -rw-r--r-- | doc/build/orm/join_conditions.rst | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/doc/build/orm/join_conditions.rst b/doc/build/orm/join_conditions.rst index 0c48bbe82..6115df5b1 100644 --- a/doc/build/orm/join_conditions.rst +++ b/doc/build/orm/join_conditions.rst @@ -576,10 +576,18 @@ the rows in both ``A`` and ``B`` simultaneously:: # 2. Create a new mapper() to B, with non_primary=True. # Columns in the join with the same name must be # disambiguated within the mapping, using named properties. - B_viacd = mapper(B, j, non_primary=True, properties={ - "b_id": [j.c.b_id, j.c.d_b_id], - "d_id": j.c.d_id - }) + # we also have to make sure the primary key of the regular "B" + # mapping is maintained. + B_viacd = mapper( + B, j, non_primary=True, primary_key=[j.c.b_id], + properties={ + "id": j.c.b_id, # so that 'id' looks the same as before + "c_id": j.c.c_id, # needed for disambiguation + "d_c_id": j.c.d_c_id, # needed for disambiguation + "b_id": [j.c.b_id, j.c.d_b_id], + "d_id": j.c.d_id, + } + ) A.b = relationship(B_viacd, primaryjoin=A.b_id == B_viacd.c.b_id) |