Correctly find references to aliased columns

sqlparser/lib/src/analysis/steps/column_resolver.dart

@@ -83,8 +83,12 @@ class ColumnResolver extends RecursiveVisitor<void> {
         final column =
             ExpressionColumn(name: name, expression: resultColumn.expression);
 
-        availableColumns.add(column);
         usedColumns.add(column);
+
+        // make this column available if there is no other with the same name
+        if (!availableColumns.any((c) => c.name == name)) {
+          availableColumns.add(column);
+        }
       }
     }
 

sqlparser/test/analysis/reference_resolver_test.dart

@@ -58,4 +58,13 @@ void main() {
       ),
     );
   });
+
+  test('resolves sub-queries', () {
+    final engine = SqlEngine()..registerTable(demoTable);
+
+    final context = engine.analyze(
+        'SELECT d.*, (SELECT id FROM demo WHERE id = d.id) FROM demo d;');
+
+    expect(context.errors, isEmpty);
+  });
 }