resolve #15, support foreign key on sql and django in from_query_sets

pyexcel_io/utils.py

@@ -37,13 +37,31 @@ def from_query_sets(column_names, query_sets):
     for row in query_sets:
         new_array = []
         for column in column_names:
-            value = getattr(row, column)
+            if '__' in column:
+                value = _get_complex_attribute(row, column)
+            else:
+                value = _get_simple_attribute(row, column)
             if isinstance(value, (datetime.date, datetime.time)):
                 value = value.isoformat()
             new_array.append(value)
         yield new_array
 
 
+def _get_complex_attribute(row, attribute):
+    attributes = attribute.split('__')
+    value = row
+    for attributee in attributes:
+        value = _get_simple_attribute(value, attributee)
+    return value
+
+
+def _get_simple_attribute(row, attribute):
+    value = getattr(row, attribute)
+    if isinstance(value, (datetime.date, datetime.time)):
+        value = value.isoformat()
+    return value
+
+
 def is_empty_array(array):
     """
     Check if an array is an array of '' or not

tests/test_sql_book.py

@@ -1,3 +1,4 @@
+import json
 from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column , Integer, String, Float, Date, DateTime, ForeignKey
@@ -10,7 +11,7 @@
 from pyexcel_io.database.sql import SQLBookWriter, SQLTableImporter, SQLTableImportAdapter
 from pyexcel_io.database.sql import SQLTableExporter, SQLTableExportAdapter, SQLBookReader
 from sqlalchemy.orm import relationship, backref
-from nose.tools import raises
+from nose.tools import raises, eq_
 import platform
 
 engine = None
@@ -29,6 +30,7 @@ class Pyexcel(Base):
     weight=Column(Float)
     birth=Column(Date)
 
+
 class Post(Base):
     __tablename__ = 'post'
     id = Column(Integer, primary_key=True)
@@ -51,6 +53,7 @@ def __init__(self, title, body, category, pub_date=None):
     def __repr__(self):
         return '<Post %r>' % self.title
 
+
 class Category(Base):
     __tablename__ = 'category'
     id = Column(Integer, primary_key=True)
@@ -339,11 +342,16 @@ def test_read(self):
         book = SQLBookReader()
         book.open_content(exporter)
         data = book.read_all()
-        import json
         for key in data.keys():
             data[key] = list(data[key])
         assert json.dumps(data) == '{"category": [["id", "name"], [1, "News"], [2, "Sports"]], "post": [["body", "category_id", "id", "pub_date", "title"], ["formal", 1, 1, "2015-01-20T23:28:29", "Title A"], ["informal", 2, 2, "2015-01-20T23:28:30", "Title B"]]}'
 
+    def test_foreign_key(self):
+        all_posts = self.session.query(Post).all()
+        column_names = ['category__name', 'title']
+        data = list(from_query_sets(column_names, all_posts))
+        eq_(json.dumps(data), '[["category__name", "title"], ["News", "Title A"], ["Sports", "Title B"]]')
+
     def tearDown(self):
         self.session.close()