Merge pull request #28 from cs50/sql-improvements

SQL improvements

Author: dmalan

src/cs50/sql.py

@@ -1,4 +1,5 @@
 import datetime
+import decimal
 import importlib
 import logging
 import re
@@ -31,7 +32,6 @@ def execute(self, text, **params):
         """
         Execute a SQL statement.
         """
-
         class UserDefinedType(sqlalchemy.TypeDecorator):
             """
             Add support for expandable values, a la https://bitbucket.org/zzzeek/sqlalchemy/issues/3953/expanding-parameter.
@@ -122,20 +122,27 @@ def process(value):
             self.logger.debug(statement)
 
             # if SELECT (or INSERT with RETURNING), return result set as list of dict objects
-            if re.search(r"^\s*SELECT\s+", statement, re.I):
-                rows = result.fetchall()
-                return [dict(row) for row in rows]
+            if re.search(r"^\s*SELECT", statement, re.I):
+
+                # coerce any decimal.Decimal objects to float objects
+                # https://groups.google.com/d/msg/sqlalchemy/0qXMYJvq8SA/oqtvMD9Uw-kJ
+                rows = [dict(row) for row in result.fetchall()]
+                for row in rows:
+                    for column in row:
+                        if isinstance(row[column], decimal.Decimal):
+                            row[column] = float(row[column])
+                return rows
 
             # if INSERT, return primary key value for a newly inserted row
-            elif re.search(r"^\s*INSERT\s+", statement, re.I):
+            elif re.search(r"^\s*INSERT", statement, re.I):
                 if self.engine.url.get_backend_name() in ["postgres", "postgresql"]:
                     result = self.engine.execute(sqlalchemy.text("SELECT LASTVAL()"))
                     return result.first()[0]
                 else:
                     return result.lastrowid
 
             # if DELETE or UPDATE, return number of rows matched
-            elif re.search(r"^\s*(?:DELETE|UPDATE)\s+", statement, re.I):
+            elif re.search(r"^\s*(?:DELETE|UPDATE)", statement, re.I):
                 return result.rowcount
 
             # if some other statement, return True unless exception