我已经在MSSQLServer 2008R2和MYSQL WorkBench 6.1上创建了一个5000万行的表。我不确定为什么这个查询在MySql上用了16秒,而在SQL-Server上却用了0秒?SELECT avg(speed) FROM tm where RoadId%5=0 and time%3=0;ps:这是在SQL-Server上创建表<em
ORDER BY DATE_FORMAT(FROM_UNIXTIME( UNIX_TIMESTAMP( ) - MAX( CAST(`time` AS UNSIGNED) ) ) ,'%e')));但是,在MySql 5.7.21中显示了下面的错误
ERROR 3029 (HY000): Expression #1 of ORDER BY contains aggregate我找不到错误代码3029的任何文档