Method extract

sql/item_jsonfunc.cc:806–879

}

bool Json_path_extractor::extract(MEM_ROOT *mem_root, String *str,
                                  Item *item_js, Item *item_jp,
                                  CHARSET_INFO *cs,
                                  MEM_ROOT_DYNAMIC_ARRAY *array_counters,
                                  const char *func_name, bool allow_wildcard)
{
  String *js= item_js->val_json(&tmp_js);
  json_path_step_t *tmp_ptr= NULL;
  int error= 0;

  if (!parsed)
  {
    String *s_p= item_jp->val_str(&tmp_path);

    if (allow_wildcard)
    {
      if (s_p &&
        json_path_setup(&p, s_p->charset(), (const uchar *) s_p->ptr(),
                       (const uchar *) s_p->ptr() + s_p->length()))
        error= true;
    }
    else
    {
      if (s_p &&
        path_setup_nwc(&p, s_p->charset(), (const uchar *) s_p->ptr(),
                       (const uchar *) s_p->ptr() + s_p->length()))
        error= true;
    }

    if (error)
    {
      report_path_error_ex(s_p->ptr(), &p, func_name, 1,
                           Sql_condition::WARN_LEVEL_WARN);
      return true;
    }

    parsed= constant;
  }

  if (item_js->null_value || item_jp->null_value)
    return true;

  json_scan_start(&je, js->charset(), (const uchar*)js->ptr(),
                                    (const uchar*)js->end());
  str->length(0);
  str->set_charset(cs);

  cur_step= &p.steps;
  tmp_ptr= (json_path_step_t*)(p.steps.buffer);
continue_search:
  if (json_find_path(&je, &p, &tmp_ptr, array_counters))
    goto error_return;

  if (json_read_value(&je))
    goto error_return;

  if (je.value_type == JSON_VALUE_NULL)
    goto error_return;