Mysql 5.7 JSON 与 物联网设备上数完美结合

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MySQL 5.7.15 新特性一 (json)

更多更浓参考官网
https://dev.mysql.com/doc/refman/5.7/en/json.html

一、测试过程

1.创建库表

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create database veh_history; use veh_history; CREATE TABLE `t_equipment_traffic` (   `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '自增主键',   `cn` char(17) NOT NULL COMMENT '设备号',   `st` datetime NOT NULL  COMMENT '采集时间',   `description` json,   PRIMARY KEY (`id`,`st`),   KEY `idx_cn_ct` (`cn`),   KEY `idx_st` (`st`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COMMENT='历史数据' PARTITION BY RANGE (to_days(st)) (PARTITION p201601 VALUES LESS THAN (to_days('2016-12-01')), PARTITION p201612 VALUES LESS THAN (to_days('2017-01-01')), PARTITION p201701 VALUES LESS THAN (to_days('2017-02-01')), PARTITION p201702 VALUES LESS THAN (to_days('2017-03-01')) );

2.插入json类型测试数据

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insert into `t_equipment_traffic` (cn,st,description) values ('liaoa12345roiland',now(), '{"time":"2015-01-01 13:00:00","speed":"100","result":"fail"}'); insert into `t_equipment_traffic` (cn,st,description) values ('liaoa12345roiland',now(), '{"time":"2017-01-01 13:00:00","speed":"110","result":"fail"}'); insert into `t_equipment_traffic` (cn,st,description) values ('liaoa12345roiland',now(), '{"time":"2017-01-02 13:00:00","speed":"110","result":"sucessed"}');

3.json简单查询方法

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select cn,description from t_equipment_traffic where cn='liaoa12345roiland'; select * from t_equipment_traffic where description ->'$.time' > '2016-12-31'; select cn,json_extract(description,'$.speed') AS 'speed',json_extract(description,'$.result') AS 'result' from t_equipment_traffic;

4.创建虚拟列

1 2	ALTER TABLE t_equipment_traffic  ADD description_speed int(10) GENERATED ALWAYS AS (description->'$.speed') VIRTUAL;

5.创建索引

1	alter table  t_equipment_traffic add index idx_speed (description_speed);

6.查看执行计划
explain partitions select * from t_equipment_traffic where description_speed=100;

二、小结
1.mysql 5.7 已开始支持json数据类型，存储引擎使用Innodb
2.对于物联网设备上数存储完全可以采用json，大数据量，经常会变更字段的场景十分适合。
3.uuid+json+innodb+partition 解决数据手动同步可能导致的主键冲突，经常字段变更，数据的定期删除。

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