Javaコーディング条件文

条件(score≧50)を指定して検索します。

   public final void findUseConditions() {
       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", 50);
       mainQuery.put("score", subQuery);

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

       DBCursor cursor1 = coll.find(mainQuery);

       System.out.println("count = " + cursor1.count());

       while (cursor1.hasNext()) {
           BasicDBObject obj = (BasicDBObject)cursor1.next();
           System.out.println(obj.toString());
       }
   }

結果表示は以下になります。

query json = { "score" : { "$gte" : 50}}
count = 4
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d3"} , "name" : "user-3" , "team" : 0.0 , "score" : 82.0}
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d4"} , "name" : "user-4" , "team" : 1.0 , "score" : 79.0}
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d6"} , "name" : "user-6" , "team" : 0.0 , "score" : 79.0}
{ "_id" : { "$oid" : "5184c79dc401ef5c9cf0f8d7"} , "name" : "user-7" , "team" : 1.0 , "score" : 93.0}