diff --git a/src/sql/resolver/dml/ob_select_resolver.cpp b/src/sql/resolver/dml/ob_select_resolver.cpp
index 528866a5e3..eddd939de2 100644
--- a/src/sql/resolver/dml/ob_select_resolver.cpp
+++ b/src/sql/resolver/dml/ob_select_resolver.cpp
@@ -943,7 +943,18 @@ int ObSelectResolver::check_order_by()
         for (int64_t i = 0; OB_SUCC(ret) && i < select_items.count(); ++i) {
           ObRawExpr *expr = select_items.at(i).expr_;
           if (OB_FAIL(select_item_exprs.push_back(expr))) {
-            LOG_WARN("fail to push back expr", K(ret));
+              LOG_WARN("fail to push back expr", K(ret));
+            // Support non-standard semantics in oracle
+            //
+          } else if (T_FUN_SYS_TO_CHAR == expr->get_expr_type() && expr->get_param_count() == 1) {
+            if (OB_ISNULL(expr->get_param_expr(0))) {
+              ret = OB_ERR_UNEXPECTED;
+              LOG_WARN("to_char has no child expr", K(ret));
+            } else if (expr->get_param_expr(0)->get_result_type().is_number()) {
+              if (OB_FAIL(select_item_exprs.push_back(expr->get_param_expr(0)))) {
+                LOG_WARN("fail to push back expr", K(ret));
+              }
+            }
           }
         }
         if (OB_SUCC(ret)) {