小编And*_*man的帖子

我有以下 SQL 语句针对 MariaDB 10.1.26 运行，具有约 2.000 行并具有即时结果。

select value, datetime from Schuppen 
where (value = (select min(value) from Schuppen where (measure = 'temp') 
    and datetime between '2018-11-01 00:00:00' and '2018-11-02 00:00:00')) 
and datetime between '2018-11-01 00:00:00' and '2018-11-02 00:00:00';

当我将以下语句与日期时间字段的变量一起使用时，执行需要大约 5.5 秒。

set @startdate = cast('2018-11-01 00:00:00' as datetime);
set @enddate = cast('2018-11-02 00:00:00' as datetime);
select value, datetime from Schuppen 
where (value = (select min(value) from Schuppen where (measure = 'temp') 
    and datetime between @startdate and @enddate)) 
and …