Do not use parameters for COUNT(*)

cedk · cedk · commit 21dc7a84e27d · 2025-06-18T15:36:56.000+02:00
Closes #95
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,5 @@
+* Do not use parameters for COUNT(*)
+
 Version 1.6.0 - 2025-05-02
 * Fix position of order_by parameters in Select query
 * Add support for weak reference on SQL objects
diff --git a/sql/aggregate.py b/sql/aggregate.py
@@ -4,7 +4,6 @@
 
 __all__ = ['Avg', 'BitAnd', 'BitOr', 'BoolAnd', 'BoolOr', 'Count', 'Every',
     'Max', 'Min', 'Stddev', 'Sum', 'Variance']
-_sentinel = object()
 
 
 class Aggregate(Expression):
@@ -169,20 +168,31 @@ class BoolOr(Aggregate):
     _sql = 'BOOL_OR'
 
 
+class _Star(Expression):
+    __slots__ = ()
+
+    def __str__(self):
+        return '*'
+
+    @property
+    def params(self):
+        return ()
+
+
 class Count(Aggregate):
     __slots__ = ()
     _sql = 'COUNT'
 
-    def __init__(self, expression=_sentinel, **kwargs):
-        if expression is _sentinel:
-            expression = Literal('*')
+    def __init__(self, expression=_Star(), **kwargs):
         super().__init__(expression, **kwargs)
 
     @property
     def _case_expression(self):
         expression = super(Count, self)._case_expression
-        if (isinstance(self.expression, Literal)
-                and expression.value == '*'):
+        if (isinstance(self.expression, _Star)
+                # Keep testing Literal('*') for backward compatibility
+                or (isinstance(self.expression, Literal)
+                and expression.value == '*')):
             expression = Literal(1)
         return expression
 
diff --git a/sql/tests/test_aggregate.py b/sql/tests/test_aggregate.py
@@ -42,8 +42,8 @@ def test_avg(self):
 
     def test_count_without_expression(self):
         count = Count()
-        self.assertEqual(str(count), 'COUNT(%s)')
-        self.assertEqual(count.params, ('*',))
+        self.assertEqual(str(count), 'COUNT(*)')
+        self.assertEqual(count.params, ())
 
     def test_order_by_one_column(self):
         avg = Avg(self.table.a, order_by=self.table.b)

Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
	`1`	`+* Do not use parameters for COUNT(*)`
	`2`	`+`
`1`	`3`	`Version 1.6.0 - 2025-05-02`
`2`	`4`	`* Fix position of order_by parameters in Select query`
`3`	`5`	`* Add support for weak reference on SQL objects`