SimpleDB - 子查询或嵌套的select语句？

Question

我尝试在Amazon SimpleDB中实现以下查询并获得InvalidQueryExpression，AWS错误消息：指定的查询表达式语法无效。

SelectRequest selectRequest = 
   new SelectRequest("select itemName() from Quotes where name = '" + 
      myName + 
      "' and name in (select followedName from Following)");

是否简单地不支持子查询或嵌套选择？SimpleDB？那么，我怎样才能实现像交换数据库这样的东西呢？

Answer 1

所以我发现https://forums.aws.amazon.com/thread.jspa?messageID=236456&#236456表示它不支持子查询。这是我使用的解决方法：

SelectRequest selectRequestNames = new SelectRequest("select followedName from Following where followedBy = '" + myName + "'").withConsistentRead(true);
List<Item> names = getInstance().select(selectRequestNames).getItems();

String set = "(";
for (int j = 0; j < names.size(); j++) {
    set += "'" + names.get(j).getAttributes().get(0).getValue() + "',";
}
set = set.substring(0, set.length() - 1) + ")";

SelectRequest selectRequest = new SelectRequest("select itemName() from Quotes where fbName in " + set + " and timestamp is not null order by timestamp desc").withConsistentRead(true);