use db_session for articles and sections

sections/model.py

@@ -34,11 +34,6 @@ class FullSectionSchema(Schema):
     updated_at = fields.DateTime()
     created_at = fields.DateTime()
     
-    #    @post_load
-#    def make_section(self, data):
-#        return Section.deserialize(data)
-
-
 
 class Section(Base):
     __tablename__ = 'sections'
@@ -78,7 +73,7 @@ class Section(Base):
     
     @classmethod
     def find_or_create(cls, fname):
-        s=Section.query.filter(Section.foreign_name==fname).first()
+        s=db_session.query(Section).filter(Section.foreign_name==fname).first()
         if s is None:
             s=Section(fname)
             db_session.add(s)