Question

我试图选择一个字符串的最小值，但是由于sql按字典顺序自动排序，而不是我所需的正确顺序。

我目前有3个季节，我想选择最小数量/最小数量。我目前拥有的代码是：

Select distinct season from table1 order by season desc;

当前输出的顺序是：

Spring19
Autumn19
Autumn18

但是我需要它按照季节的顺序排列：

Autumn18
Spring19
Autumn19

是否可以在不实际更改文本格式的情况下将格式更改为“日期”？还是有其他方法可以做到这一点？

谢谢：）

Answer 1

大多数数据库支持right()功能（如果不支持，则它们具有相似的功能，但名称不同）。

所以，这应该起作用：

Select distinct season
from table1
order by right(season, 2) asc, season desc;

Answer 2

with seasoncte (season_number, season_year, season) as (
  select case when left(season, length(season) -2) = "Spring" then 1
            when left(season, length(season) -2) = "Summer" then 2
            when left(season, length(season) -2) = "Autumn" then 3
            when left(season, length(season) -2) = "Winter  then 4
        end as season_number,
        cast(right(season,2 as int) as season_year,
        season
  from table1
), seasoncte2 (season_number, season_year, season) as (
   select season_number
          case when season_year < 39 then 2000 + season_year
          case else then 1900 + season_year
          end,
          season
   from seasoncte
)
select t1.season
from table1 t1
join seasoncte2 cte
on t1.season = cte.season
order by cte.season_year, cte.season_number

代码可能需要根据SQL方言进行调整。

Op没有指定。或提供rextester链接，以便可以测试代码。

通过SQL中的最小订单输出更改订单

2 个答案: