model field conversion on assignment

src/infi/clickhouse_orm/database.py

@@ -40,7 +40,7 @@ class Database(object):
         self._send(gen())
 
     def count(self, model_class, conditions=None):
-        query = 'SELECT uniq(height) FROM %s.%s' % (self.db_name, model_class.table_name())
+        query = 'SELECT count() FROM %s.%s' % (self.db_name, model_class.table_name())
         if conditions:
             query += ' WHERE ' + conditions
         r = self._send(query)

src/infi/clickhouse_orm/fields.py

@@ -38,7 +38,7 @@ class StringField(Field):
             return value
         if isinstance(value, str):
             return value.decode('UTF-8')
-        raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
+        raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
 
     def get_db_prep_value(self, value):
         if isinstance(value, unicode):
@@ -58,7 +58,7 @@ class DateField(Field):
             return DateField.class_default + datetime.timedelta(days=value)
         if isinstance(value, basestring):
             return datetime.datetime.strptime(value, '%Y-%m-%d').date()
-        raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
+        raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
 
     def get_db_prep_value(self, value):
         return value.isoformat()
@@ -78,7 +78,7 @@ class DateTimeField(Field):
             return datetime.datetime.fromtimestamp(value, pytz.utc)
         if isinstance(value, basestring):
             return datetime.datetime.strptime(value, '%Y-%m-%d %H-%M-%S')
-        raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
+        raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
 
     def get_db_prep_value(self, value):
         return int(time.mktime(value.timetuple()))
@@ -91,7 +91,7 @@ class BaseIntField(Field):
             return value
         if isinstance(value, basestring):
             return int(value)
-        raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
+        raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
 
 
 class UInt8Field(BaseIntField):
@@ -139,9 +139,9 @@ class BaseFloatField(Field):
     def to_python(self, value):
         if isinstance(value, float):
             return value
-        if isinstance(value, basestring):
+        if isinstance(value, basestring) or isinstance(value, int):
             return float(value)
-        raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
+        raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
 
 
 class Float32Field(BaseFloatField):

src/infi/clickhouse_orm/models.py

@@ -4,10 +4,12 @@ from engines import *
 
 
 class ModelBase(type):
+    '''
+    A metaclass for ORM models. It adds the _fields list to model classes.
+    '''
 
     def __new__(cls, name, bases, attrs):
         new_cls = super(ModelBase, cls).__new__(cls, name, bases, attrs)
-        #print name, bases, attrs
         # Build a list of fields, in the order they were listed in the class
         fields = [item for item in attrs.items() if isinstance(item[1], Field)]
         fields.sort(key=lambda item: item[1].creation_counter)
@@ -16,16 +18,34 @@ class ModelBase(type):
 
 
 class Model(object):
+    '''
+    A base class for ORM models.
+    '''
 
     __metaclass__ = ModelBase
     engine = None
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, **kwargs):
+        '''
+        Creates a model instance, using keyword arguments as field values.
+        Since values are immediately converted to their Pythonic type,
+        invalid values will cause a ValueError to be raised.
+        '''
         super(Model, self).__init__()
         for name, field in self._fields:
             val = kwargs.get(name, field.default)
             setattr(self, name, val)
 
+    def __setattr__(self, name, value):
+        field = self.get_field(name)
+        if field:
+            value = field.to_python(value)
+        super(Model, self).__setattr__(name, value)
+
+    def get_field(self, name):
+        field = getattr(self.__class__, name, None)
+        return field if isinstance(field, Field) else None
+
     @classmethod
     def table_name(cls):
         return cls.__name__.lower()
@@ -54,8 +74,9 @@ class Model(object):
         values = iter(parse_tsv(line))
         kwargs = {}
         for name, field in cls._fields:
-            kwargs[name] = field.to_python(values.next())
+            kwargs[name] = values.next()
         return cls(**kwargs)
+        # TODO verify that the number of values matches the number of fields
 
     def to_tsv(self):
         '''

tests/test_database.py

@@ -6,7 +6,7 @@ from infi.clickhouse_orm.fields import *
 from infi.clickhouse_orm.engines import *
 
 
-class ORMTestCase(unittest.TestCase):
+class DatabaseTestCase(unittest.TestCase):
 
     def setUp(self):
         self.database = Database('test_db')

tests/test_models.py

@@ -0,0 +1,54 @@
+import unittest
+import datetime
+import pytz
+
+from infi.clickhouse_orm.models import Model
+from infi.clickhouse_orm.fields import *
+from infi.clickhouse_orm.engines import *
+
+
+class ModelTestCase(unittest.TestCase):
+
+    def test_defaults(self):
+        # Check that all fields have their defaults
+        instance = SimpleModel()
+        self.assertEquals(instance.date_field, datetime.date(1970, 1, 1))
+        self.assertEquals(instance.datetime_field, datetime.datetime(1970, 1, 1, tzinfo=pytz.utc))
+        self.assertEquals(instance.str_field, 'dozo')
+        self.assertEquals(instance.int_field, 17)
+        self.assertEquals(instance.float_field, 0)
+
+    def test_assignment(self):
+        # Check that all fields are assigned during construction
+        kwargs = dict(
+            date_field=datetime.date(1973, 12, 6),
+            datetime_field=datetime.datetime(2000, 5, 24, 10, 22, tzinfo=pytz.utc),
+            str_field='aloha',
+            int_field=-50,
+            float_field=3.14
+        )
+        instance = SimpleModel(**kwargs)
+        for name, value in kwargs.items():
+            self.assertEquals(kwargs[name], getattr(instance, name))
+
+    def test_string_conversion(self):
+        # Check field conversion from string during construction
+        instance = SimpleModel(date_field='1973-12-06', int_field='100', float_field='7')
+        self.assertEquals(instance.date_field, datetime.date(1973, 12, 6))
+        self.assertEquals(instance.int_field, 100)
+        self.assertEquals(instance.float_field, 7)
+        # Check field conversion from string during assignment
+        instance.int_field = '99'
+        self.assertEquals(instance.int_field, 99)
+
+
+class SimpleModel(Model):
+
+    date_field = DateField()
+    datetime_field = DateTimeField()
+    str_field = StringField(default='dozo')
+    int_field = Int32Field(default=17)
+    float_field = Float32Field()
+
+    engine = MergeTree('date_field', ('int_field', 'date_field'))
+