1 files changed, 7 insertions, 6 deletions
diff --git a/app/model.py b/app/model.py
index ec555d3..5ae2ead 100644
--- a/app/model.py
+++ b/app/model.py
@@ -102,15 +102,12 @@ class Category (UserModel):
             return '<Category "%s">' % self.name
 
 
-class Expense (UserModel):
+class CategoryModel (db.Model):
     """Abstract base class for expenses: Adds the common fields
     and establishes the connection to `Category`.
     """
     __abstract__ = True
 
-    description = Column(db.Unicode(50))
-    expense     = ReqColumn(ExpNum)
-
     @declared_attr
     def category_id(cls):
         return ReqColumn(db.Integer, db.ForeignKey(Category.id))
@@ -120,7 +117,9 @@ class Expense (UserModel):
         return db.relationship(Category, innerjoin = True)
 
 
-class SingleExpense (Expense):
+class SingleExpense (UserModel, CategoryModel):
+    description = Column(db.Unicode(50))
+    expense     = ReqColumn(ExpNum)
     year = ReqColumn(db.Integer)
     month = ReqColumn(db.SmallInteger)
     day = ReqColumn(db.SmallInteger)
@@ -140,7 +139,9 @@ class SingleExpense (Expense):
         self.day = d.day
 
 
-class ConstExpense (Expense):
+class ConstExpense (UserModel, CategoryModel):
+    description = Column(db.Unicode(50))
+    expense     = ReqColumn(ExpNum)
     months  = ReqColumn(db.SmallInteger)
     start   = ReqColumn(db.Date, index = True)
     end     = ReqColumn(db.Date, index = True)