一. 常用查询:

1. 查询一条数据:(多用于保存时判断db中是否已有当前数据,这里 is  精确匹配,模糊匹配 使用 regex...)

public PageUrl getByUrl(String url) {        return findOne(new Query(Criteria.where("url").is(url)),PageUrl.class);    }

2. 查询多条数据:linkUrl.id 属于分级查询

public List
     
       getPageUrlsByUrl(int begin, int end,String linkUrlid) {                Query query = new Query();        query.addCriteria(Criteria.where("linkUrl.id").is(linkUrlid));        return find(query.limit(end - begin).skip(begin), PageUrl.class);            }
     

3. 模糊查询:

public long getProcessLandLogsCount(List
     
       conditions)    {        Query query = new Query();        if (conditions != null && conditions.size() > 0) {            for (Condition condition : conditions) {                query.addCriteria(Criteria.where(condition.getKey()).regex(".*?\\" +condition.getValue().toString()+ ".*"));             }        }        return count(query, ProcessLandLog.class);    }
     

4. gte: 大于等于,lte小于等于...注意查询的时候各个字段的类型要和mongodb中数据类型一致

public List
     
       getProcessLandLogs(int begin,int end,List
      
        conditions,String orderField,Direction direction)    {        Query query = new Query();        if (conditions != null && conditions.size() > 0) {            for (Condition condition : conditions) {                if(condition.getKey().equals("time")){                    query.addCriteria(Criteria.where("time").gte(condition.getValue())); //gte: 大于等于                }else if(condition.getKey().equals("insertTime")){                    query.addCriteria(Criteria.where("insertTime").gte(condition.getValue()));                }else{                    query.addCriteria(Criteria.where(condition.getKey()).is(condition.getValue()));                }            }        }        return find(query.limit(end - begin).skip(begin).with(new Sort(new Sort.Order(direction, orderField))), ProcessLandLog.class);    } public List
       
         getDpsLandsByTime(int begin, int end, Date beginDate,Date endDate) {
       return find(new Query(Criteria.where("updateTime").gte(beginDate).lte(endDate)).limit(end - begin).skip(begin),     DpsLand.class);  }
       
      
     

    查询字段不存在的数据

public List
     
       getGoodsDetails2(int begin, int end) {        Query query = new Query();        query.addCriteria(Criteria.where("goodsSummary").not());        return find(query.limit(end - begin).skip(begin),GoodsDetail.class);    }
     

 

 

5. 查询数量:

public long getPageInfosCount(List
     
       conditions) {        Query query = new Query();        if (conditions != null && conditions.size() > 0) {            for (Condition condition : conditions) {
                    query.addCriteria(Criteria.where(condition.getKey()).is(condition.getValue()));            }        }        return count(query, PageInfo.class);    }
     

6. 更新一条数据的一个字段:

public WriteResult updateTime(PageUrl pageUrl) {        String id = pageUrl.getId();        return updateFirst(new Query(Criteria.where("id").is(id)),Update.update("updateTime", pageUrl.getUpdateTime()), PageUrl.class); }

7. 更新一条数据的多个字段:

//调用更新private void updateProcessLandLog(ProcessLandLog processLandLog,            int crawlResult) { List
     
       fields = new ArrayList
      
       (); List
       
      
     

8. 删除数据:

public void deleteObject(Class
     
       clazz,String id) {        remove(new Query(Criteria.where("id").is(id)),clazz);    }
     

9.保存数据:

//插入一条数据 public void saveObject(Object obj) {        insert(obj);    } //插入多条数据    public void saveObjects(List
     
       objects) {        for(T t:objects){            insert(t);        }    }