鉴于这三个文件:db.test.save({"_id":1,"foo":"bar1","xKey":"xVal1"});db.test.save({"_id":2,"foo":"bar2","xKey":"xVal2"});db.test.save({"_id":3,"foo":"bar3","xKey":"xVal3"});以及引用这些文档的一组单独的信息:[{"_id":1,"foo":"bar1Upd"},{"_id":2,"foo":"bar2Upd"}]是否可以在单个操作中更新两个引用文档(1和2)上的“foo”?我知道我可以遍历数组并一个一个地执行它们,但我有数千个文档,这