Question

目前正在解决一个挑战问题，我一直试图解决我面临的问题但却无法解决。您的专业知识将受到高度赞赏。

以下是问题：

旋转OCCUPATIONS中的Occupation列，以便每个Name按字母顺序排序并显示在其相应的Occupation下面。输出列标题应分别为Doctor，Professor，Singer和Actor。

我的解决方案

SELECT
    [Doctor],
    [Professor],
    [Singer],
    [Actor]
FROM
    (SELECT 
         ROW_NUMBER() OVER (PARTITION BY Occupation ORDER BY Name) ma,
         [Name],
         [Occupations] 
     FROM 
         Occupation
    ) AS source 
PIVOT
    ( MAX([Name]) FOR [occupation] IN ([Doctor],[Professor],[Singer],[Actor]) ) as pv
ORDER BY ma

错误消息

ERROR 1064 (42000) at line 5: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '[Doctor],
    [Professor],
    [Singer],
    [Actor]
FROM
    (SELECT 
         ' at line 2

等待你的回复。感谢

Answer 1

Mysql不支持PIVOT运营商

使用conditional aggregate来转动数据。

由于名称被拆分为4个不同的列，因此在旋转数据后按名称排序并没有多大意义。

select 
Occupations,
max(case when occupation = 'Doctor' then name end) as Doctor,
max(case when occupation = 'Professor' then name end) as Professor,
max(case when occupation = 'Singer' then name end) as Singer,
max(case when occupation = 'Actor' then name end) as Actor
from Occupation
Group by Occupations

您也应该使用反引号[]

而不是方括号``

Answer 2

对于Mysql，可以这样解决：

set @d=0, @p=0, @s=0, @a=0;

select min(Doctor), min(Professor), min(Singer), min(Actor)
from(
  select case 
            when Occupation='Doctor' then (@d:=@d+1)
            when Occupation='Professor' then (@p:=@p+1)
            when Occupation='Singer' then (@s:=@s+1)
            when Occupation='Actor' then (@a:=@a+1) 
            end as Rowline,
        case when Occupation='Doctor' then Name end as Doctor,
        case when Occupation='Professor' then Name end as Professor,
        case when Occupation='Singer' then Name end as Singer,
        case when Occupation='Actor' then Name end as Actor
  from OCCUPATIONS
  order by Name
) as temp
group by Rowline;

希望这能解决您的问题。

在SQL中使用Pivot时出现错误代码

2 个答案: