Merge pull request #74 from azavea/isnull-values

Add support for isnull on key/value pairs

django_hstore/fields.py

@@ -78,6 +78,7 @@ def south_field_triple(self):
     HStoreField.register_lookup(HStoreLessThanOrEqual)
     HStoreField.register_lookup(HStoreContains)
     HStoreField.register_lookup(HStoreIContains)
+    HStoreField.register_lookup(HStoreIsNull)
 
 
 class DictionaryField(HStoreField):

django_hstore/lookups.py

@@ -7,10 +7,11 @@
     LessThan,
     LessThanOrEqual,
     Contains,
-    IContains
+    IContains,
+    IsNull
 )
 
-from django_hstore.query import get_cast_for_param
+from django_hstore.query import get_cast_for_param, get_value_annotations
 
 
 __all__ = [
@@ -20,15 +21,16 @@
     'HStoreLessThan',
     'HStoreLessThanOrEqual',
     'HStoreContains',
-    'HStoreIContains'
+    'HStoreIContains',
+    'HStoreIsNull'
 ]
 
 
 class HStoreLookupMixin(object):
     def __init__(self, lhs, rhs, *args, **kwargs):
         # We need to record the types of the rhs parameters before they are converted to strings
         if isinstance(rhs, dict):
-            self.value_annot = dict((key, type(subvalue)) for key, subvalue in six.iteritems(rhs))
+            self.value_annot = get_value_annotations(rhs)
         super(HStoreLookupMixin, self).__init__(lhs, rhs)
 
 
@@ -118,3 +120,22 @@ def as_postgresql(self, qn, connection):
 
 class HStoreIContains(IContains, HStoreContains):
     pass
+
+
+class HStoreIsNull(IsNull):
+
+    def as_postgresql(self, qn, connection):
+        lhs, lhs_params = self.process_lhs(qn, connection)
+
+        if isinstance(self.rhs, dict):
+            param = self.rhs
+            param_keys = list(param.keys())
+            conditions = []
+
+            for key in param_keys:
+                op = 'IS NULL' if param[key] else 'IS NOT NULL'
+                conditions.append('(%s->\'%s\') %s' % (lhs, key, op))
+
+            return (" AND ".join(conditions), lhs_params)
+
+        return super(HStoreIsNull, self).as_sql(qn, connection)

django_hstore/query.py

@@ -88,12 +88,18 @@ def get_cast_for_param(value_annot, key):
         return '::float8'
     elif issubclass(value_annot[key], Decimal):
         return '::numeric'
-    elif issubclass(value_annot[key], bool):
+    elif value_annot[key] in (True, False):
         return '::boolean'
     else:
         return ''
 
 
+def get_value_annotations(param):
+    # We need to store the actual value for booleans, not just the type, for isnull
+    get_type = lambda v: v if isinstance(v, bool) else type(v)
+    return dict((key, get_type(subvalue)) for key, subvalue in six.iteritems(param))
+
+
 class HStoreWhereNode(WhereNode):
 
     def add(self, data, *args, **kwargs):
@@ -108,8 +114,8 @@ def add(self, data, *args, **kwargs):
         if isinstance(original_value, dict):
             len_children = len(self.children) if self.children else 0
 
-            value_annot = dict((key, type(subvalue))
-                               for key, subvalue in six.iteritems(original_value))
+            value_annot = get_value_annotations(original_value)
+
             # We should be able to get the normal child node here, but it is not returned in Django 1.5
             super(HStoreWhereNode, self).add(data, *args, **kwargs)
 
@@ -202,6 +208,15 @@ def make_atom(self, child, qn, connection):
                     raise ValueError('invalid value')
 
             elif lookup_type == 'isnull':
+                if isinstance(param, dict):
+                    param_keys = list(param.keys())
+                    conditions = []
+
+                    for key in param_keys:
+                        op = 'IS NULL' if value_annot[key] else 'IS NOT NULL'
+                        conditions.append('(%s->\'%s\') %s' % (field, key, op))
+
+                    return (" AND ".join(conditions), [])
                 # do not perform any special format
                 return super(HStoreWhereNode, self).make_atom(child, qn, connection)
 

doc/doc.asciidoc

@@ -449,6 +449,13 @@ Something.objects.filter(data__contains=['a', 'b'])
 
 # subset by single key
 Something.objects.filter(data__contains=['a'])
+
+# filter by is null on individual key/value pairs
+Something.objects.filter(data__isnull={'a': True})
+Something.objects.filter(data__isnull={'a': True, 'b': False})
+
+# filter by is null on the column works as normal
+Something.objects.filter(data__isnull=True)
 ----
 
 

tests/django_hstore_tests/tests.py

@@ -153,6 +153,18 @@ def test_nullable_getitem(self):
         with self.assertRaises(KeyError):
             n.data['test']
 
+    def test_null_values(self):
+        null_v = DataBag.objects.create(name="test", data={"v": None})
+        nonnull_v = DataBag.objects.create(name="test", data={"v": "item"})
+
+        r = DataBag.objects.filter(data__isnull={"v": True})
+        self.assertEqual(len(r), 1)
+        self.assertEqual(r[0], null_v)
+
+        r = DataBag.objects.filter(data__isnull={"v": False})
+        self.assertEqual(len(r), 1)
+        self.assertEqual(r[0], nonnull_v)
+
     def test_named_querying(self):
         alpha, beta = self._create_bags()
         self.assertEqual(DataBag.objects.get(name='alpha'), alpha)