如何使用其java驱动程序在mongodb中使用'或'以及'和'操作？

Question

db.mycol.find(
    {
        "likes": { $gt: 10 }, 
        $or: [
            {"by": "tutorials point"},
            {"title": "MongoDB Overview"}
        ]
    }).pretty()

它的等效java代码是什么？

Answer 1

您可以尝试这样的事情：

BasicDBObject gtQuery = new BasicDBObject();
gtQuery.put("likes", new BasicDBObject("$gt", 10))

BasicDBObject q1 = new BasicDBObject("by", "tutorials point");  
BasicDBObject q2 = new BasicDBObject("title", "MongoDB Overview");    
BasicDBList or = new BasicDBList();
or.add(q1);
or.add(q2);
BasicDBObject orQuery = new BasicDBObject("$or", or);

List<BasicDBObject> obj = new ArrayList<BasicDBObject>();
obj.add(gtQuery);
obj.add(orQuery );    

BasicDBObject andQuery = new BasicDBObject();
andQuery.put("$and", obj);

System.out.println(andQuery.toString());

DBCursor cursor = mycol.find(andQuery);
    while (cursor.hasNext()) {
        System.out.println(cursor.next());
}