From 252ab17c7dc5f1cfd1a5173fb6d9e4b819e1ebb7 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Fri, 13 Aug 2010 14:25:58 -0400
Subject: [PATCH] - Added basic math expression coercion for Numeric->Integer,
 so that resulting type is Numeric regardless of the direction of the
 expression.

---
 CHANGES                 |  5 +++++
 lib/sqlalchemy/types.py |  5 +++++
 test/sql/test_types.py  | 24 ++++++++++++++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/CHANGES b/CHANGES
index 24bd97b288..da9f3dca0e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -77,6 +77,11 @@ CHANGES
     the outer query.  [ticket:1852]
     
 - sql
+  - Added basic math expression coercion for 
+    Numeric->Integer,
+    so that resulting type is Numeric regardless
+    of the direction of the expression.
+    
   - Changed the scheme used to generate truncated
     "auto" index names when using the "index=True"
     flag on Column.   The truncation only takes
diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py
index 91eb352751..777353714a 100644
--- a/lib/sqlalchemy/types.py
+++ b/lib/sqlalchemy/types.py
@@ -1024,20 +1024,25 @@ class Numeric(_DateAffinity, TypeEngine):
             operators.mul:{
                 Interval:Interval,
                 Numeric:Numeric,
+                Integer:Numeric,
             },
             # Py2K
             operators.div:{
                 Numeric:Numeric,
+                Integer:Numeric,
             },
             # end Py2K
             operators.truediv:{
                 Numeric:Numeric,
+                Integer:Numeric,
             },
             operators.add:{
                 Numeric:Numeric,
+                Integer:Numeric,
             },
             operators.sub:{
                 Numeric:Numeric,
+                Integer:Numeric,
             }
         }
 
diff --git a/test/sql/test_types.py b/test/sql/test_types.py
index 91e4ec177a..a80e761d73 100644
--- a/test/sql/test_types.py
+++ b/test/sql/test_types.py
@@ -904,6 +904,30 @@ class ExpressionTest(TestBase, AssertsExecutionResults, AssertsCompiledSQL):
         expr = func.current_date() - column('foo', types.TIMESTAMP)
         eq_(expr.type._type_affinity, types.Interval)
     
+    def test_numerics_coercion(self):
+        from sqlalchemy.sql import column
+        import operator
+        
+        for op in (
+            operator.add,
+            operator.mul,
+            operator.truediv,
+            operator.sub
+        ):
+            for other in (Numeric(10, 2), Integer):
+                expr = op(
+                        column('bar', types.Numeric(10, 2)),
+                        column('foo', other)
+                       )
+                assert isinstance(expr.type, types.Numeric)
+                expr = op(
+                        column('foo', other),
+                        column('bar', types.Numeric(10, 2))
+                       )
+                assert isinstance(expr.type, types.Numeric)
+
+        
+        
     def test_expression_typing(self):
         expr = column('bar', Integer) - 3
         
-- 
2.47.2