集北卡卡罗特的博客

鄙人在项目中遇到一个业务要计算月同比和环比，需要查询一个时间字段中多个时间范围的记录，实现的SQL示例如下： select * from fault_happen where train_code = '710' and fault_level = '3' and (happen_time >= '2020-07-01 00:00:00' and happen_time < '2020-08-01 00:00:00' OR happen_time >= '2020-06-01 00:00

MySQL max()函数用于找出指定记录集中字段值最大的记录： SELECT MAX(combine_time) from fault_time; 查询结果如下： ---------------------------------------------------------------------分割线-------------------------------------------...

如题，limit不能与in/all/any/some连用， update fault_time set combine_time = '' where combine_time in (SELECT LENGTH(max_len.combine_time) from (SELECT LENGTH(combine_time) from phm_fault_repair ORDER BY LENGTH...