resolve alias issue

Author: HazelYuAhiru

core/query_parser.py

@@ -309,6 +309,10 @@ def parse_expression(self, expr, aliases: dict = None) -> Node:
             aliases = {}
 
         if isinstance(expr, str):
+            # Alias reference: if a later clause uses a SELECT alias token
+            # (e.g. ORDER BY dept_name), reuse the aliased expression node.
+            if expr in aliases:
+                return aliases[expr]
             # Column reference
             if '.' in expr:
                 parts = expr.split('.', 1)

data/asts.py

@@ -1351,6 +1351,7 @@ def _ast_query_42() -> QueryNode:
     where_condition = OperatorNode(where_123, "AND", strpos_cond)
     where_clause = WhereNode([where_condition])
     # GROUP BY 1, 2
+    # TODO: replace it by actual column nodes
     group_by_clause = GroupByNode([LiteralNode(1), LiteralNode(2)])
     return QueryNode(
         _select=select_clause,