sql - sql 按硬编码值排序

Question

我有以下查询：

select 'junior' as type, value
from mytable
union
select 'intermediate' as type, value
from mytable
union
select 'senior' as type, value
from mytable

它返回以下数据：

type          value

Intermediate     10    
Junior            5
Senior            1

我只需要重新排序它看起来像这样

Junior          5
Intermediate   10        
Senior          1

我无法弄清楚使用哪个 order by 子句来实现按自定义特定值排序，我将如何实现这一点？

Answer 1

我不知道您是否理解得很好，但我会再提取一列，例如带有整数值的“序列”。它将提供应用自定义订单的能力。

举个例子：

select results.type, results.value, results.sequence 
from (    
    select 'junior' as type, value, 0 as sequence
    from mytable
    union
    select 'intermediate' as type, value, 1 as sequence
    from mytable
    union
    select 'senior' as type, value, 2 as sequence
    from mytable
) as results order by results.sequence

Answer 2

您可以通过添加排序键列进行排序，也可以根据值添加简单的 case 语句。

-- Sort with Case statement
with sourceData as
(
  select 'junior' type, 5 value
  union all
  select 'intermediate' type, 10 value
  union all
  select 'senior' type, 1 value
)
select * 
from sourceData
order by 
  case type
    when 'junior' then 0
    when 'intermediate' then 1
    when 'senior' then 2
    else null
  end

用于测试的SQL Fiddle 。

Answer 3

您需要添加第三列，例如 sortorder。然后，为其分配适当的整数值，

select 'junior' as type, value, 1 as sortorder
from mytable
union
select 'intermediate' as type, value, 2 as sortorder
from mytable
union
select 'senior' as type, value, 3 as sortorder
from mytable
order by 3

Answer 4

试试这个。

select TYPE, value from (select type,value, row_number() over (order by type) as rowno from #mytable union select type, value, row_number() over (order by type) as rowno from #mytable union select type,value , row_number() over (order by type) as rowno from #mytable)a order by 2 desc