Cómo pivotar filas en columnas (pivotar personalizado)


Tengo una tabla de base de datos Sql similar a la siguiente:

Day   Period    Subject

Mon   1         Ch
Mon   2         Ph
Mon   3         Mth
Mon   4         CS
Mon   5         Lab1
Mon   6         Lab2
Mon   7         Lab3
Tue   1         Ph
Tue   2         Ele
Tue   3         Hu
Tue   4         Ph
Tue   5         En
Tue   6         CS2
Tue   7         Mth

Me gustaría que se muestre de la siguiente manera: Tipo de tabla cruzada o Pivote

Day   P1   P2   P3   P4   P5   P6   P7

Mon   Ch   Ph   Mth  CS2  Lab1 Lab2 Lab3
Tue   Ph   Ele  Hu   Ph   En   CS2  Mth

¿Cuál sería la forma ideal de hacerlo? ¿Puede alguien mostrarme el código Sql, por favor?

Author: ahsteele, 2010-06-25

6 answers

Probablemente podrías hacerlo con la función PIVOT, pero prefiero el método de la vieja escuela:

SELECT
    dy,
    MAX(CASE WHEN period = 1 THEN subj ELSE NULL END) AS P1,
    MAX(CASE WHEN period = 2 THEN subj ELSE NULL END) AS P2,
    MAX(CASE WHEN period = 3 THEN subj ELSE NULL END) AS P3,
    MAX(CASE WHEN period = 4 THEN subj ELSE NULL END) AS P4,
    MAX(CASE WHEN period = 5 THEN subj ELSE NULL END) AS P5,
    MAX(CASE WHEN period = 6 THEN subj ELSE NULL END) AS P6,
    MAX(CASE WHEN period = 7 THEN subj ELSE NULL END) AS P7
FROM
    Classes
GROUP BY
    dy
ORDER BY
    CASE dy
        WHEN 'Mon' THEN 1
        WHEN 'Tue' THEN 2
        WHEN 'Wed' THEN 3
        WHEN 'Thu' THEN 4
        WHEN 'Fri' THEN 5
        WHEN 'Sat' THEN 6
        WHEN 'Sun' THEN 7
        ELSE 8
    END
  • Cambié algunos nombres de columna para evitar palabras reservadas
 17
Author: Tom H,
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2010-06-25 19:41:03

Solo en caso de que quieras el nuevo método escolar. (La instrucción Pivot debería funcionar en SQL2005+, el bit VALUES solo para los datos de ejemplo SQL2008)

WITH ExampleData AS
(
SELECT X.*
  FROM (VALUES  
('Mon', 1, 'Ch'),
('Mon', 2, 'Ph'),
('Mon', 3, 'Mth'),
('Mon', 4, 'CS'),
('Mon', 5, 'Lab1'),
('Mon', 6, 'Lab2'),
('Mon', 7, 'Lab3'),
('Tue', 1, 'Ph'),
('Tue', 2, 'Ele'),
('Tue', 3, 'Hu'),
('Tue', 4, 'Ph'),
('Tue', 5, 'En'),
('Tue', 6, 'CS2'),
('Tue', 7, 'Mth')
) AS X (Day,   Period,    Subject)
)

SELECT Day, [1] AS P1, [2] AS P2,[3] AS P3, [4] AS P4, [5] AS P5,[6] AS P6,[7] AS P7
FROM ExampleData
PIVOT  
(  
Max(Subject)  
FOR Period IN ([1], [2],[3],[4], [5],[6], [7])  
) AS PivotTable; 

Resultado

Day  P1   P2   P3   P4   P5   P6   P7
---- ---- ---- ---- ---- ---- ---- ----
Mon  Ch   Ph   Mth  CS   Lab1 Lab2 Lab3
Tue  Ph   Ele  Hu   Ph   En   CS2  Mth
 12
Author: Martin Smith,
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2010-06-25 19:50:02

Podrías intentarlo...

SELECT DISTINCT Day,
       (SELECT Subject
            FROM my_table mt2
            WHERE mt2.Day = mt.Day AND
                  Period  = 1) AS P1,
       (SELECT Subject
            FROM my_table mt2
            WHERE mt2.Day = mt.Day AND
                  Period  = 2) AS P2,
   .
   .
   etc
   .
   .
   .
   (SELECT Subject
        FROM my_table mt2
        WHERE mt2.Day = mt.Day AND
              Period  = 7) AS P7
FROM my_table mt;

Pero no puedo decir que me guste mucho. Mejor que nada, sin embargo.

 1
Author: Brian Hooper,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2010-06-25 19:40:41

Use cross apply para obtener todos los valores en un formato delimitado por comas en una sola columna. en lugar de "7" columnas diferentes. La siguiente consulta se puede utilizar para cualquier asignación de columnas-> filas

SELECT DISTINCT Day, [DerivedColumn] FROM <Table> A CROSS APPLY ( SELECT Period + ',' FROM <Table> B WHERE A.Day = B.Day Order By Period FOR XML PATH('') ) AS C (DerivedColumn)

Obtendrá [Ch,Ph,Mth,CS2,Lab1,Lab2,Lab3] en una columna para Mon y así sucesivamente ... Puede usar esto como una tabla para consultar cualquier día en particular.

Espero que esto ayude

 1
Author: Baaju,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2010-06-25 19:48:24
DECLARE @TIMETABLE TABLE (
    [Day]       CHAR(3),
    [Period]    TINYINT,
    [Subject]   CHAR(5)
)
INSERT INTO @TIMETABLE([Day], [Period], [Subject])
VALUES
    ('Mon', 1, 'Ch'),
    ('Mon', 2, 'Ph'),
    ('Mon', 3, 'Mth'),
    ('Mon', 4, 'CS'),
    ('Mon', 5, 'Lab1'),
    ('Mon', 6, 'Lab2'),
    ('Mon', 7, 'Lab3'),
    ('Tue', 1, 'Ph'),
    ('Tue', 2, 'Ele'),
    ('Tue', 3, 'Hu'),
    ('Tue', 4, 'Ph'),
    ('Tue', 5, 'En'),
    ('Tue', 6, 'CS2'),
    ('Tue', 7, 'Mth')

SELECT 
    [Day],
    MAX(CASE [Period] WHEN 1 THEN [Subject] END) AS P1,
    MAX(CASE [Period] WHEN 2 THEN [Subject] END) AS P2,
    MAX(CASE [Period] WHEN 3 THEN [Subject] END) AS P3,
    MAX(CASE [Period] WHEN 4 THEN [Subject] END) AS P4,
    MAX(CASE [Period] WHEN 5 THEN [Subject] END) AS P5,
    MAX(CASE [Period] WHEN 6 THEN [Subject] END) AS P6,
    MAX(CASE [Period] WHEN 7 THEN [Subject] END) AS P7
FROM @TIMETABLE
GROUP BY [Day]
 1
Author: Flipping,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2015-01-20 08:19:29
with pivot_data as
(
select [day], -- groping column
period, -- spreading column
subject -- aggreate column
from pivot_tb
)
select [day],  [1] AS P1, [2] AS P2,[3] AS P3, [4] AS P4, [5] AS P5,[6] AS P6,[7] AS P7
from pivot_data
pivot ( max(subject) for period in ([1], [2],[3],[4], [5],[6], [7]) ) as p;
 0
Author: mr_eclair,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2013-12-20 07:07:01