fix broken test case

doc/source/sqlalchemy.rst

@@ -81,6 +81,8 @@ Now suppose we have these more complex tables:
 
     >>> from sqlalchemy import ForeignKey, DateTime
     >>> from sqlalchemy.orm import relationship, backref
+    >>> import sys
+    >>> PY33 = (sys.version_info[0] == 3 and sys.version_info[1] == 3)
     >>> class Post(Base):
     ...     __tablename__ = 'post'
     ...     id = Column(Integer, primary_key=True)
@@ -99,6 +101,8 @@ Now suppose we have these more complex tables:
     ...             pub_date = datetime.utcnow()
     ...         self.pub_date = pub_date
     ...         self.category = category
+    ...         if PY33:
+    ...             self.category_id = category.id
     ... 
     ...     def __repr__(self):
     ...         return '<Post %r>' % self.title

tests/test_sql_book.py

@@ -12,6 +12,8 @@
 from pyexcel_io.sqlbook import SQLTableReader, SQLTableWriter
 from sqlalchemy.orm import relationship, backref
 from nose.tools import raises
+import sys
+PY33 = (sys.version_info[0] == 3 and sys.version_info[1] == 3)
 
 
 engine=create_engine("sqlite:///tmp.db")
@@ -43,6 +45,8 @@ def __init__(self, title, body, category, pub_date=None):
             pub_date = datetime.utcnow()
         self.pub_date = pub_date
         self.category = category
+        if PY33:
+            self.category_id = category.id
 
     def __repr__(self):
         return '<Post %r>' % self.title