(goctl)fix: #3328 (#3348)

Co-authored-by: Kevin Wan <wanjunfeng@gmail.com>

tools/goctl/model/sql/example/sql/user.sql

@@ -30,5 +30,6 @@ CREATE TABLE `student`
 ) DEFAULT NULL,
   `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `update_time` timestamp NULL DEFAULT NULL,
+  `delete_time` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP,
   PRIMARY KEY (`type`) USING BTREE
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;