如何使用Java使用ObjectIds创建查询? [英] How to create query with ObjectIds using java?

问题描述

我有一组ID，例如:

["51eae104c2e6b6c222ec3432", "51eae104c2e6b6c222ec3432", "51eae104c2e6b6c222ec3432"]

我需要使用这组ID查找所有文档.

I need to find all documents using this set of ids.

    BasicDBObject query = new BasicDBObject(); 
    BasicDBList list = new BasicDBList();
    ObjectId ob1 = new ObjectId("51eae100c2e6b6c222ec3431");
    ObjectId ob2 = new ObjectId("51eae100c2e6b6c222ec3432");
    list.add(ob1);
    list.add(ob2);
    query.append("_id", new BasicDBObject("$in", list));

此查询找不到任何内容，因为它与

This query can't find anything because it is same as

{ "_id" : { "$in" : [ { "$oid" : "51eae100c2e6b6c222ec3431"} , { "$oid" : "51eae100c2e6b6c222ec3432"}]}}

要找到必须的东西

{_id:{$in:[ObjectId("51eae100c2e6b6c222ec3431") , ObjectId("51eae104c2e6b6c222ec3432")]}}

但是我不知道如何使用Java在列表中制作ObjectId("51eae100c2e6b6c222ec3431")

but I don't know how to make ObjectId("51eae100c2e6b6c222ec3431") in list using java

推荐答案

{ "$oid" : "51eae100c2e6b6c222ec3431"}与ObjectId("51eae100c2e6b6c222ec3431")相同，只是格式不同.

{ "$oid" : "51eae100c2e6b6c222ec3431"} is the same as ObjectId("51eae100c2e6b6c222ec3431") just in a different format.

有关不同格式，请参见此页面: http://docs.mongodb .org/manual/reference/mongodb-extended-json/

See this page for the different formats: http://docs.mongodb.org/manual/reference/mongodb-extended-json/

如果查询未找到任何文档(并且您确定它们在集合中存在)，则还有其他问题.我将仔细检查您要连接的服务器，并首先检查数据库和集合的名称.

If the query is not finding any documents (and you are sure they are present in the collection) then there is some other issue. I would double check the server(s) you are connecting to and the name of the database and collection first.

Rob.

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