MySQL自定义时间间隔抽稀

表设计
- 数据如下
- 按分钟抽稀
- 按小时抽稀
- 按天抽稀

表设计

create table monitor
(tid       varchar(255)   not null,save_date datetime       not null,tlevel    decimal(10, 2) null,primary key (tid, save_date)
);

数据如下

在这里插入图片描述

按分钟抽稀

SELECT t2.tid,t2.save_date,t2.tlevel,t2.gid,t2.seq
FROM (SELECT t1.tid,t1.save_date,t1.tlevel,t1.gid,ROW_NUMBER() over ( PARTITION BY t1.tid, t1.gid ORDER BY t1.tid, t1.gid ) AS seqFROM (SELECT tid,save_date,tlevel,FLOOR(UNIX_TIMESTAMP(save_date) / (60 * 1)) AS gidFROM monitorORDER BY tid,save_date) t1ORDER BY t1.tid,t1.save_date) t2
WHERE t2.seq = 1

按小时抽稀

SELECT t2.tid,t2.save_date,t2.tlevel,t2.gid,t2.seq
FROM (SELECT t1.tid,t1.save_date,t1.tlevel,t1.gid,ROW_NUMBER() over ( PARTITION BY t1.tid, t1.gid ORDER BY t1.tid, t1.gid ) AS seqFROM (SELECT tid,save_date,tlevel,FLOOR(UNIX_TIMESTAMP(save_date) / (60 * 60 * 1)) AS gidFROM monitorORDER BY tid,save_date) t1ORDER BY t1.tid,t1.save_date) t2
WHERE t2.seq = 1

按天抽稀

SELECT t2.tid,t2.save_date,t2.tlevel,t2.gid,t2.seq
FROM (SELECT t1.tid,t1.save_date,t1.tlevel,t1.gid,ROW_NUMBER() over ( PARTITION BY t1.tid, t1.gid ORDER BY t1.tid, t1.gid ) AS seqFROM (SELECT tid,save_date,tlevel,FLOOR(UNIX_TIMESTAMP(save_date) / (60 * 60 * 24 * 1)) AS gidFROM monitorORDER BY tid,save_date) t1ORDER BY t1.tid,t1.save_date) t2
WHERE t2.seq = 1