复制MySQL查询的结果集
我希望根据表中日期的工作日平均出特定查询的值,并在其他日期复制它。我知道这个解释令人困惑,请参见下面的示例复制MySQL查询的结果集,mysql,Mysql,我希望根据表中日期的工作日平均出特定查询的值,并在其他日期复制它。我知道这个解释令人困惑,请参见下面的示例 Eg:- Table Structure - ID, Value, Date Expected Result- Avg(value), Weekname(day) 12.23 , Mon 12.23 , Tue 12.23 , Wed 12.23 , Thu 12.23 , Fri 34.56 , Sat 56.34 , Sun 也就是说,周
Eg:- Table Structure -
ID, Value, Date
Expected Result-
Avg(value), Weekname(day)
12.23 , Mon
12.23 , Tue
12.23 , Wed
12.23 , Thu
12.23 , Fri
34.56 , Sat
56.34 , Sun
也就是说,周一到周五的值是相同的
Current Result
Avg(value), Weekname(day)
12.23 , Mon
34.56 , Sat
56.34 , Sun
查询如下所示-
select avg(value)
,daynameofweek(date)
from table
group by (CASE WHEN DAYOFWEEK(DATE) NOT BETWEEN 2 and 6 THEN DAYOFWEEK(DATE) END)
提前谢谢你的帮助
编辑-添加示例数据集
预期结果
Avg(Value) daynameofweek(date)
1.625 Monday
1.625 Tuesday
1.625 Wednesday
1.625 Thursday
1.625 Friday
1.300 Saturday
1.702 Sunday
您显示的结果是周一到周五的“MON”,但这是DBMS任意选择的,您也可以以“WED”结束,因为这一天也在分组范围内。所以从这里得到一个确定的值开始。然后加入一个组成的日表:
select
days.dayname,
data.avg_value
from
(
select
case when dayofweek(date) between 2 and 6 then 2 else dayofweek(date) end as day
avg(value) as avg_value
from table
group by case when dayofweek(date) between 2 and 6 then 2 else dayofweek(date) end
) data
join
(
select 1 as day, 'SUN' as dayname, 7 as sortkey union all
select 2 as day, 'MON' as dayname, 1 as sortkey union all
select 2 as day, 'TUE' as dayname, 2 as sortkey union all
select 2 as day, 'WED' as dayname, 3 as sortkey union all
select 2 as day, 'THU' as dayname, 4 as sortkey union all
select 2 as day, 'FRI' as dayname, 5 as sortkey union all
select 7 as day, 'SAT' as dayname, 6 as sortkey
) days on days.day = data.day
order by data.sortkey;
(如果我没记错的话,MySQL允许按别名分组(
按天分组
),这不符合标准。如果您更喜欢,可以使用它。)请在postWhy 2和6中包含示例数据集和表定义?这背后的逻辑是什么?复制值直到间隙结束?请重新表述问题。2指星期一的工作日,6指星期五。请参阅:示例数据集似乎与原始问题并不相关
select
days.dayname,
data.avg_value
from
(
select
case when dayofweek(date) between 2 and 6 then 2 else dayofweek(date) end as day
avg(value) as avg_value
from table
group by case when dayofweek(date) between 2 and 6 then 2 else dayofweek(date) end
) data
join
(
select 1 as day, 'SUN' as dayname, 7 as sortkey union all
select 2 as day, 'MON' as dayname, 1 as sortkey union all
select 2 as day, 'TUE' as dayname, 2 as sortkey union all
select 2 as day, 'WED' as dayname, 3 as sortkey union all
select 2 as day, 'THU' as dayname, 4 as sortkey union all
select 2 as day, 'FRI' as dayname, 5 as sortkey union all
select 7 as day, 'SAT' as dayname, 6 as sortkey
) days on days.day = data.day
order by data.sortkey;