查询组数据中最新记录的集合

实例：现有一张统计表，是以task_id和start_time作为联合主键的，每一个任务可以启动多次，这样一来同一个task_id就会对应多个start_time即多条统计记录，现在要求将所有的任务统计出来，也就是查询出task_id唯一的集合，每条任务对应的是最新的一条统计记录

<select id="selectLatestStatistics" resultType="com.haitao55.spider.common.dos.StatisticsDO">
        <!-- 方法一:使用in关键字 -->
        select
        <include refid="allColumns" />
        from statistics 
        where start_time in(
        select max(start_time) from statistics
        group by task_id)
        
        <!-- 方法二：使用any_value关键字 -->
        select task_id taskId,max(start_time) startTime,any_value(end_time) endTime, 
               any_value(success_count) successCount, any_value(failed_count) failedCount,
               any_value(offline_count) offlineCount, any_value(total_count) totalCount
        from   statistics
        group by task_id
        
        <!-- 方法三：连表查询 -->
        select  a.task_id as taskId, a.start_time as startTime, a.end_time as endTime, 
                a.success_count as successCount, a.failed_count as failedCount, 
                a.offline_count as offlineCount, a.total_count as totalCount
        from statistics a,(
            select task_id,max(start_time) startTime
            from statistics
            group by task_id) b
        where a.task_id = b.task_id
        and a.start_time = b.startTime
    </select>