fix varchar

Author: geooo109

sqlglot/optimizer/annotate_types.py

@@ -346,7 +346,9 @@ def _get_scope_selects(self, scope: Scope) -> dict[str, dict[str, t.Any]]:
                             if alias_node:
                                 col_types[field_col.name] = alias_node.type
                         else:
-                            col_types[field_col.name] = exp.DType.VARCHAR
+                            col_types[field_col.name] = exp.DataType.build(
+                                "VARCHAR", dialect=self.dialect
+                            )
 
                         # Value column types from the IN source columns
                         src = first.this if is_pivot_alias else first