MongoDB的CRUD操作（java Util ）

1、保存插入操作：

public static synchronized String insert(DBObject record) {

        DBCollection col = MongoDB.getDBCollection(TABLE_NAME);

        record.put("time", new Date().getTime());

        WriteResult result = col.insert(record);

        //当前插入表的_id

        return record.get("_id").toString();

   }

注意：col.insert(record)执行成功后 record可以获取_id 可以通过 record.get("_id")是否为空判断保存是否为空!

 

2、更新编辑操作：

public static synchronized int edit(DBObject record) {

        DBCollection col = MongoDB.getDBCollection(TABLE_NAME);

        // 检查是否有对应的obj_id存在

        BasicDBObject queryObj = new BasicDBObject();

        queryObj.put("_id", record.get("_id"));

        DBCursor dc = col.find(queryObj);

        if (dc.count() < 1) {

            return NO_RECORD_EXIST;

        } 

        // 保存数据

        record.removeField("_id");

        WriteResult result = col.update(queryObj, new BasicDBObject("$set", record));

        return result.getN();

    }

注意：在更新数据前要将被更新的数据中_id移除掉 否则报错，queryObj是更新的查询条件，record是更新的记录，record中不能包含_id...

 

3、删除操作：

public static synchronized int del(DBObject record, OlaCloudContent olaCloudContent) {

        DBCollection col = MongoDB.getDBCollection(TABLE_NAME);

        // 检查是否有对应的obj_id存在

        DBCursor dc = col.find(record);

        if (dc.count() < 1) {

            return NO_RECORD_EXIST;

        }// 删除数据

        WriteResult result = col.remove(record);

        OpLog.AddOpLog(olaCloudContent.getUserName(), TABLE_NAME, "del_key", record.toString());

        return result.getN();

    }

    

 

4、查询操作：

public static synchronized CorpusAnswerWrap find(DBObject record,DBObject sort,int limit){

        CorpusAnswerWrap answerWrap = new CorpusAnswerWrap();

        List<AnswerEntity> answerList = new ArrayList<AnswerEntity>();

        DBCollection col = MongoDB.getDBCollection(TABLE_NAME);

        DBCursor dc = col.find(record).sort(sort);

        if(limit > 0){

            dc.limit(limit);

        }

        answerWrap.setTotalCount(dc.count());

        while(dc.hasNext()){

            AnswerEntity entity = answerWrap.new AnswerEntity();

            entity.setRecord(dc.next());

            answerList.add(entity);

        }

        answerWrap.setDatas(answerList.toArray(new AnswerEntity[answerList.size()]));

        return answerWrap;

    }