如何使用Java在MongoDB中同时使用AND和OR子句执行查询? [英] How to execute queries with both AND and OR clauses in MongoDB with Java?

问题描述

我想使用Java Driver 3.2在MongoDB 3.2中执行查询，该驱动程序同时包含 $ and 和 $ or 子句.

I want to execute query in MongoDB 3.2 with Java Driver 3.2, which contains both $and and $or clauses at the same time.

使用参考，我尝试了以下方法:

With the reference, I tried the following approach:

List<Document> criteria1 = new ArrayList<>();
List<Document> criteria2 = new ArrayList<>();

criteria1.add(new Document("fetchStatus", new Document("$gte", FetchStatus.PROCESSED_NLP.getID())));
criteria1.add(new Document("fetchStatus", new Document("$lte", fetchStatusParam)));
criteria1.add(new Document("episodeID", new Document("$in", episodeIDs)));

criteria2.add(new Document("fetchStatus", new Document("$eq", PROCESSED_FETCH.getID())));
criteria2.add(new Document("isFullTextRet", new Document("$eq", false)));

BasicDBList or = new BasicDBList();
or.add(criteria1);
or.add(criteria2);

DBObject query = new BasicDBObject("$or", or);
ArrayList<Document> results = dbC_Coll.find(query).into(new ArrayList<>());

其中 criteria1 和 criteria2 应该与 $ or 连接的位置，而在 criteria1 子句中，$ and 应该适用.

Where the criteria1 and criteria2 should be connected with $or while within criteria1 clause the $and should be applied.

问题是，在MongoDB Java驱动程序3.2中没有这样的方法，我得到了无法解决方法find(com.mongodb.DBObject)错误.

The problem is that in MongoDB Java Driver 3.2 there is such no method and I get the Cannot resolve method find(com.mongodb.DBObject) error.

我的问题:
如何编写诸如(A&& B)||之类的查询(X& Y)在MongoDB Java驱动程序3.2中?

My question:
How can I compose a query such as (A && B) || (X && Y) in MongoDB Java Driver 3.2?

推荐答案

就个人而言，我发现构造对象序列的混乱要少得多，就像U用JSON结构来增强可读性一样.但是无论您在何处看到 {} ，还是在任何地方，只要看到 [] ， List 仍然是 Document():

Personally, I find it far less confusing to construct the object sequences just like U would with a JSON structure to enhance readability. But it's still just Document() wherever you see {} and List wherever you see []:

Document query = new Document(
    "$or", Arrays.asList(
        // First document in $or
        new Document(
            "fetchStatus", 
            new Document( "$gte", FetchStatus.PROCESSED_NLP.getID() )
            .append("$lte", fetchStatusParam)
        )
        .append("episodeID", new Document( "$in", episodeIDs)),
        // Second document in $or
        new Document("fetchStatus", PROCESSED_FETCH.getID())
        .append("isFullTextRet", false)
    )
);

与以下基本相同:

   {
       "$or": [
           {
               "fetchStatus": { 
                   "$gte": FetchStatus.PROCESS_NLP.getID(),
                   "$lte": fetchStatusParam
               },
               "episodeID": { "$in": episodeIDs }
           },
           {
               "fetchStatus": PROCESSED_FETCH.getID(),
               "isFullTextRet": false
           }
       ]
   }

也不需要显式" $ eq 运算符，因为无论如何，等于"实际上是查询属性中值分配的默认含义.

Also there is no need for "explicit" $eq operators, since "equals" is actually the default meaning of a value assignment in a query property anyway.

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