qq_40798764的博客

mysql处理地址模糊查询加’%address%‘利用字符拼接函数CONCAT(CONCAT(’%’,#{address,jdbcType=VARCHAR},’%’))

Mysql性能优化 force index(index_createtime) ：表示强制使用该索引，一般加在所要使用的表的后面，如下： SELECT a.devEUI devEUI, a.fport fport, a.complete_data completeData, a.create_time createTime from se...

案例1 SELECT u.interfaceDataId AS interfaceDataId, u.sensorNumber AS sensorNumber, u.tPort AS tPort, u.aPort AS aPort, u.threeTPort AS threeTPort, u.syncTime AS syncTime, t.address AS address FRO...