# mybatis-plus使用sum,,count,distinct等函数的方法

QueryWrapper<User> wrapper1 = new QueryWrapper<>(); wrapper1.select("count(user_id) as userids", "sum(age) as ages") .in("user_id","1,2,3"); Map<String, Object> map = this.getMap(wrapper1); map.get("userids"); // 也可以将map转换为实体类，只不过字段需要对应 JSON.parseObject(JSON.toJSONString(map), ScoreData.class);