Question

表名称：职业

**Name  Occupation**  
Samantha    Doctor    
Julia   Actor
Maria   Actor
Meera   Singer
Ashely  Professor
Ketty   Professor
Christeen   Professor
Jane    Actor
Jenny   Doctor
Priya   Singer

目标是编写一个查询，该查询将“透视”上述表数据，以便显示以下结果：

Jenny    Ashley     Meera  Jane
Samantha Christeen  Priya  Julia
NULL     Ketty      NULL   Maria

我写了以下查询：

 WITH pivot_data AS
(
SELECT Occupation as Occupation1,  -- Grouping Column
Occupation, -- Spreading Column
Name -- Aggregate Column
FROM Occupations
)
SELECT  [Doctor], [Professor], [Singer], [Actor]
FROM pivot_data 
PIVOT (max(Name) 
       FOR Occupation IN ([Doctor], [Professor], [Singer], [Actor])
                                                            ) AS p;

不幸的是，上述查询给出了以下错误结果：

Doctor  Professor   Singer  Actor    
NULL    NULL    NULL    Maria    
Samantha    NULL    NULL    NULL    
NULL    Ketty   NULL    NULL    
NULL    NULL    Priya   NULL

有人可以发布将显示所需结果的sql查询吗？（此外，如果您可以使用sql server“ pivot”命令执行一个查询，而另一个使用Out sql server“ pivot”命令进行查询，这将非常有帮助。）

Answer 1

我不会为此使用数据透视。条件聚合更容易编写和理解。它的性能几乎总是略胜一筹。

首先，我必须将数据转换为可消耗的东西。这是您以后应该发布此类信息的方式。

declare @Something table
(
    Name varchar(20)
    , Occupation varchar(20)
)

insert @Something values
('Samantha', 'Doctor')
, ('Julia', 'Actor')
, ('Maria', 'Actor')
, ('Meera', 'Singer')
, ('Ashely', 'Professor')
, ('Ketty', 'Professor')
, ('Christeen', 'Professor')
, ('Jane', 'Actor')
, ('Jenny', 'Doctor')
, ('Priya', 'Singer')
;

现在，我们可以使用此数据轻松地生成您的输出。

with NumberedRows as
(
    select * 
        , RowNum = ROW_NUMBER() over(partition by Occupation order by name)
    from @Something
)

select Doctor = max(case when nr.Occupation = 'Doctor' then nr.Name end)
    , Professor = max(case when nr.Occupation = 'Professor' then nr.Name end)
    , Singer = max(case when nr.Occupation = 'Singer' then nr.Name end)
    , Actor = max(case when nr.Occupation = 'Actor' then nr.Name end)
from NumberedRows nr
group by nr.RowNum

SQL Server查询专注于“透视”包含非数字数据的表

1 个答案: