JavaコーディングAND文

AND条件を指定する時のコーディング方法です。条件は、30≦ score ≦ 70 です。

   public final void findUseAnd(){
       Mongo conn = null;

       try {
           conn = new Mongo("localhost", 27017);
 
       } catch (Exception e) {
           e.printStackTrace();
       }

       WriteConcern wc = new WriteConcern(1, 2000);
       conn.setWriteConcern(wc);

       DB db = conn.getDB("blog_app");
       DBCollection coll = db.getCollection("users");

       BasicDBObject mainQuery = new BasicDBObject();

       BasicDBObject subQuery = new BasicDBObject("$gte", 30);
       subQuery.append("$lte", 70);

       mainQuery.put("score", subQuery);

       System.out.println("query json = " + mainQuery.toString());

       DBCursor cursor = coll.find(mainQuery);

       System.out.println("count = " + cursor.count());

       while (cursor.hasNext()) {
           BasicDBObject obj = (BasicDBObject)cursor.next();
           System.out.println(obj.toString());
       }
   }

結果は以下の通りです。

query json = { "score" : { "$gte" : 30 , "$lte" : 70}}
count = 2
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d1"} , "name" : "user-1" , "team" : 1.0 , "score" : 38.0}
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d5"} , "name" : "user-5" , "team" : 2.0 , "score" : 43.0}