fix(compiler): make decimal arguments optional

Author: roastedramen

clickhouse_sqlalchemy/drivers/compilers/typecompiler.py

@@ -82,7 +82,13 @@ def visit_float64(self, type_, **kw):
         return 'Float64'
 
     def visit_numeric(self, type_, **kw):
-        return 'Decimal(%s, %s)' % (type_.precision, type_.scale)
+        if type_.precision is None:
+            return "Decimal"
+        elif type_.scale is None:
+            return "Decimal(%(precision)s)" % {"precision": type_.precision}
+        else:
+            return ("Decimal(%(precision)s, %(scale)s)" %
+                    {"precision": type_.precision, "scale": type_.scale})
 
     def visit_boolean(self, type_, **kw):
         return 'Bool'

tests/types/test_numeric.py

@@ -1,6 +1,6 @@
 from decimal import Decimal
 
-from sqlalchemy import Column, Numeric
+from sqlalchemy import Column, Numeric, select, cast, column
 from sqlalchemy.sql.ddl import CreateTable
 
 from clickhouse_sqlalchemy import types, engines, Table
@@ -36,6 +36,30 @@ def test_create_table_decimal_symlink(self):
             'CREATE TABLE test (x Decimal(10, 2)) ENGINE = Memory'
         )
 
+    def test_scale_and_precision(self):
+        self.assertEqual(
+            self.compile(cast(10, Numeric(10, 2))),
+            "CAST(%(param_1)s AS Decimal(10, 2))"
+        )
+
+    def test_no_scale(self):
+        self.assertEqual(
+            self.compile(cast(10, Numeric(10))),
+            "CAST(%(param_1)s AS Decimal(10))"
+        )
+
+    def test_no_precision(self):
+        self.assertEqual(
+            self.compile(cast(10, Numeric())),
+            "CAST(%(param_1)s AS Decimal)"
+        )
+
+    def test_division_works(self):
+        self.assertEqual(
+            self.compile(select(column('x') / column('y'))),
+            "SELECT x / CAST(y AS Decimal) AS anon_1"
+        )
+
 
 class NumericTestCase(BaseTestCase):
     table = Table(