adding dynamic columns to models (which aren't working yet)

working on the QuerySet class
adding additional tests around model saving and loading

cassandraengine/columns.py

@@ -14,7 +14,7 @@ class BaseColumn(object):
         :param primary_key: bool flag, there can be only one primary key per doc
         :param db_field: the fieldname this field will map to in the database
         :param default: the default value, can be a value or a callable (no args)
-        :param null: bool, is the field nullable?
+        :param null: boolean, is the field nullable?
         """
         self.primary_key = primary_key
         self.db_field = db_field

cassandraengine/models.py

@@ -25,10 +25,6 @@ class BaseModel(object):
             if k not in values:
                 setattr(self, k, None)
 
-    @classmethod
-    def _column_family_definition(cls):
-        pass
-
     @classmethod
     def find(cls, pk):
         """ Loads a document by it's primary key """
@@ -39,6 +35,16 @@ class BaseModel(object):
         """ Returns the object's primary key, regardless of it's name """
         return getattr(self, self._pk_name)
 
+    #dynamic column methods
+    def __getitem__(self, key):
+        return self._dynamic_columns[key]
+
+    def __setitem__(self, key, val):
+        self._dynamic_columns[key] = val
+
+    def __delitem__(self, key):
+        del self._dynamic_columns[key]
+
     def validate(self):
         """ Cleans and validates the field values """
         for name, col in self._columns.items():
@@ -47,11 +53,9 @@ class BaseModel(object):
 
     def as_dict(self):
         """ Returns a map of column names to cleaned values """
-        values = {}
+        values = self._dynamic_columns or {}
         for name, col in self._columns.items():
             values[name] = col.to_database(getattr(self, name, None))
-
-        #TODO: merge in dynamic columns
         return values
 
     def save(self):

cassandraengine/query.py

@@ -1,3 +1,5 @@
+import copy
+
 from cassandraengine.connection import get_connection
 
 class QuerySet(object):
@@ -5,16 +7,18 @@ class QuerySet(object):
     #TODO: querysets should be executed lazily
     #TODO: conflicting filter args should raise exception unless a force kwarg is supplied
 
-    def __init__(self, model, query={}):
+    def __init__(self, model, query_args={}):
         super(QuerySet, self).__init__()
         self.model = model
+        self.query_args = query_args
         self.column_family_name = self.model.objects.column_family_name
 
         self._cursor = None
 
     #----query generation / execution----
     def _execute_query(self):
-        pass
+        conn = get_connection()
+        self._cursor = conn.cursor()
 
     def _generate_querystring(self):
         pass
@@ -27,39 +31,61 @@ class QuerySet(object):
 
     #----Reads------
     def __iter__(self):
-        pass
+        if self._cursor is None:
+            self._execute_query()
+        return self
+
+    def _get_next(self):
+        """
+        Gets the next cursor result
+        Returns a db_field->value dict
+        """
+        cur = self._cursor
+        values = cur.fetchone()
+        if values is None: return None
+        names = [i[0] for i in cur.description]
+        value_dict = dict(zip(names, values))
+        return value_dict
 
     def next(self):
-        pass
+        values = self._get_next() 
+        if values is None: raise StopIteration
+        return values
 
     def first(self):
-        conn = get_connection()
-        cur = conn.cursor()
         pass
 
     def all(self):
-        pass
+        return QuerySet(self.model)
 
     def filter(self, **kwargs):
-        pass
+        qargs = copy.deepcopy(self.query_args)
+        qargs.update(kwargs)
+        return QuerySet(self.model, query_args=qargs)
 
     def exclude(self, **kwargs):
+        """
+        Need to invert the logic for all kwargs
+        """
         pass
 
+    def count(self):
+        """
+        Returns the number of rows matched by this query
+        """
+
     def find(self, pk):
         """
         loads one document identified by it's primary key
         """
+        #TODO: make this a convenience wrapper of the filter method
         qs = 'SELECT * FROM {column_family} WHERE {pk_name}=:{pk_name}'
         qs = qs.format(column_family=self.column_family_name,
                        pk_name=self.model._pk_name)
         conn = get_connection()
-        cur = conn.cursor()
+        self._cursor = conn.cursor()
-        cur.execute(qs, {self.model._pk_name:pk})
+        self._cursor.execute(qs, {self.model._pk_name:pk})
-        values = cur.fetchone()
+        return self._get_next()
-        names = [i[0] for i in cur.description]
-        value_dict = dict(zip(names, values))
-        return value_dict
 
 
     #----writes----

cassandraengine/tests/columns/test_validation.py

@@ -0,0 +1,16 @@
+#tests the behavior of the column classes
+
+from cassandraengine.tests.base import BaseCassEngTestCase
+
+from cassandraengine.columns import BaseColumn
+from cassandraengine.columns import Bytes
+from cassandraengine.columns import Ascii
+from cassandraengine.columns import Text
+from cassandraengine.columns import Integer
+from cassandraengine.columns import DateTime
+from cassandraengine.columns import UUID
+from cassandraengine.columns import Boolean
+from cassandraengine.columns import Float
+from cassandraengine.columns import Decimal
+
+

cassandraengine/tests/model/test_model_io.py

@@ -1,3 +1,4 @@
+from unittest import skip
 from cassandraengine.tests.base import BaseCassEngTestCase
 
 from cassandraengine.models import Model
@@ -7,20 +8,56 @@ class TestModel(Model):
     count   = columns.Integer()
     text    = columns.Text()
     
+#class TestModel2(Model):
+    
 class TestModelIO(BaseCassEngTestCase):
 
     def setUp(self):
         super(TestModelIO, self).setUp()
         TestModel.objects._create_column_family()
 
-    def tearDown(self):
-        super(TestModelIO, self).tearDown()
-        TestModel.objects._delete_column_family()
-
     def test_model_save_and_load(self):
+        """
+        Tests that models can be saved and retrieved
+        """
         tm = TestModel.objects.create(count=8, text='123456789')
         tm2 = TestModel.objects.find(tm.pk)
 
         for cname in tm._columns.keys():
             self.assertEquals(getattr(tm, cname), getattr(tm2, cname))
 
+    def test_model_updating_works_properly(self):
+        """
+        Tests that subsequent saves after initial model creation work
+        """
+        tm = TestModel.objects.create(count=8, text='123456789')
+
+        tm.count = 100
+        tm.save()
+
+        tm2 = TestModel.objects.find(tm.pk)
+        self.assertEquals(tm.count, tm2.count)
+
+    def test_nullable_columns_are_saved_properly(self):
+        """
+        Tests that nullable columns save without any trouble
+        """
+
+    @skip
+    def test_dynamic_columns(self):
+        """
+        Tests that items put into dynamic columns are saved and retrieved properly
+
+        Note: seems I've misunderstood how arbitrary column names work in Cassandra
+        skipping for now
+        """
+        #TODO:Fix this
+        tm = TestModel(count=8, text='123456789')
+        tm['other'] = 'something'
+        tm['number'] = 5
+        tm.save()
+
+        tm2 = TestModel.objects.find(tm.pk)
+        self.assertEquals(tm['other'], tm2['other'])
+        self.assertEquals(tm['number'], tm2['number'])
+