Fix Decimal128 and Decimal256 types_check #274

clickhouse_driver/columns/decimalcolumn.py

@@ -8,18 +8,22 @@
 class DecimalColumn(FormatColumn):
     py_types = (Decimal, float, int)
     max_precision = None
-    int_size = None
 
     def __init__(self, precision, scale, types_check=False, **kwargs):
         self.precision = precision
         self.scale = scale
         super(DecimalColumn, self).__init__(**kwargs)
 
         if types_check:
-            max_signed_int = (1 << (8 * self.int_size - 1)) - 1
-
             def check_item(value):
-                if value < -max_signed_int or value > max_signed_int:
+                parts = str(value).split('.')
+                int_part = parts[0]
+                frac_part = parts[1] if len(parts) > 1 else ''
+
+                if len(int_part) > precision:
+                    raise ColumnTypeMismatchException(value)
+
+                if len(frac_part) > scale:
                     raise ColumnTypeMismatchException(value)
 
             self.check_item = check_item
@@ -80,13 +84,11 @@ def _read_data(self, n_items, buf, nulls_map=None):
 class Decimal32Column(DecimalColumn):
     format = 'i'
     max_precision = 9
-    int_size = 4
 
 
 class Decimal64Column(DecimalColumn):
     format = 'q'
     max_precision = 18
-    int_size = 8
 
 
 class Decimal128Column(DecimalColumn, Int128Column):

tests/columns/test_decimal.py

@@ -140,7 +140,7 @@ def test_max_precisions(self):
 
     def test_nullable(self):
         with self.create_table('a Nullable(Decimal32(3))'):
-            data = [(300.42, ), (None, ), ]
+            data = [(300.42, ), (None, )]
             self.client.execute(
                 'INSERT INTO test (a) VALUES', data
             )
@@ -158,7 +158,7 @@ def test_nullable(self):
 
     def test_no_scale(self):
         with self.create_table('a Decimal32(0)'):
-            data = [(2147483647, ), ]
+            data = [(2147483647, )]
             self.client.execute(
                 'INSERT INTO test (a) VALUES', data
             )
@@ -171,7 +171,7 @@ def test_no_scale(self):
             self.assertEqual(inserted, [(Decimal('2147483647'), )])
 
     def test_type_mismatch(self):
-        data = [(2147483649,), ]
+        data = [(2147483649, )]
         with self.create_table('a Decimal32(0)'):
             with self.assertRaises(errors.TypeMismatchError) as e:
                 self.client.execute(
@@ -187,6 +187,24 @@ def test_type_mismatch(self):
 
             self.assertIn('Column a', str(e.exception))
 
+    def test_type_mismatch_scale(self):
+        data = [(1.234,)]
+        with self.create_table('a Decimal32(2)'):
+            with self.assertRaises(errors.TypeMismatchError) as e:
+                self.client.execute(
+                    'INSERT INTO test (a) VALUES', data, types_check=True
+                )
+
+            self.assertIn('1.234 for column "a"', str(e.exception))
+
+            # Without types_check decimal will be cropped.
+            self.client.execute('INSERT INTO test (a) VALUES', data)
+            query = 'SELECT * FROM test'
+            inserted = self.emit_cli(query)
+            self.assertEqual(inserted, '1.23\n')
+            inserted = self.client.execute(query)
+            self.assertEqual(inserted, [(Decimal('1.23'), )])
+
     def test_preserve_precision(self):
         data = [(1.66, ), (1.15, )]