From d0234c764d282dbb6a817fad3aec6f288970607c Mon Sep 17 00:00:00 2001
From: joe <joe@autistici.org>
Date: Sun, 12 May 2013 12:25:55 +0200
Subject: [PATCH] Fixing issue with two-way referenced relations in the
sqlalchemy interface (closes issue #13)
---
configdb/db/interface/sa_generator.py | 20 ++++++++++++++++----
configdb/db/interface/sa_interface.py | 4 ++--
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/configdb/db/interface/sa_generator.py b/configdb/db/interface/sa_generator.py
index 48a1ebc..ba45157 100644
--- a/configdb/db/interface/sa_generator.py
+++ b/configdb/db/interface/sa_generator.py
@@ -8,6 +8,7 @@ class SqlAlchemyGenerator(object):
def __init__(self, schema_obj):
self.schema = schema_obj
+ self.defined_relations = []
def _audit_table_def(self):
return """
@@ -76,6 +77,13 @@ class %(class_name)s(Base):
field.name, ', '.join(args))
def _sa_field_relation_def(self, entity, field):
+ assoc_table = self._sa_assoc_table_name(field)
+ if assoc_table in self.defined_relations:
+ # In this case, we don't need a backref (it already exists)
+ return '%s = relationship("%s", secondary=%s)' % (
+ field.name,
+ field.remote_name.capitalize(),
+ assoc_table + '_table')
return '%s = relationship("%s", secondary=%s, backref="%s")' % (
field.name,
field.remote_name.capitalize(),
@@ -83,12 +91,17 @@ class %(class_name)s(Base):
pl.plural(entity.name))
def _sa_field_assoc_table_def(self, entity, field):
+ table_name = self._sa_assoc_table_name(field)
+ if table_name in self.defined_relations:
+ #we have a 2-way used relation, and do not want to re-define it
+ return ""
+ self.defined_relations.append(table_name)
return """
%s_table = Table('%s', Base.metadata,
Column('left_id', Integer, ForeignKey('%s.id')),
Column('right_id', Integer, ForeignKey('%s.id')))""" % (
- self._sa_assoc_table_name(field),
- self._sa_assoc_table_name(field),
+ table_name,
+ table_name,
field.local_name,
field.remote_name)
@@ -96,7 +109,7 @@ class %(class_name)s(Base):
tbls = sorted([field.local_name, field.remote_name])
tbls.append(field.relation_id)
return '%s_%s_assoc_%s' % tuple(tbls)
-
+
def generate(self):
out = ['from sqlalchemy import *',
'from sqlalchemy.orm import *',
@@ -106,4 +119,3 @@ class %(class_name)s(Base):
out.append(self._sa_entity_aux_tables(ent))
out.append(self._sa_entity_def(ent))
return '\n'.join(out)
-
diff --git a/configdb/db/interface/sa_interface.py b/configdb/db/interface/sa_interface.py
index b39442b..00600fa 100644
--- a/configdb/db/interface/sa_interface.py
+++ b/configdb/db/interface/sa_interface.py
@@ -56,7 +56,7 @@ class SqlAlchemyDbInterface(base.DbInterface):
self.engine = create_engine(uri, pool_recycle=1800)
self.Session.configure(bind=self.engine)
Base.metadata.create_all(self.engine)
-
+
def _load_schema(self):
with tempfile.NamedTemporaryFile() as schema_file:
schema_gen = sa_generator.SqlAlchemyGenerator(self._schema)
@@ -94,7 +94,7 @@ class SqlAlchemyDbInterface(base.DbInterface):
def get_by_name(self, entity_name, object_name, session):
return session.query(self._get_class(entity_name)).filter_by(
name=object_name).first()
-
+
def find(self, entity_name, query, session):
classobj = self._get_class(entity_name)
entity = self._schema.get_entity(entity_name)
--
GitLab