Configuración del esquema :
create table history (date datetime, name varchar(10), value int);
insert history values
('20130101', 'user1', 123),
('20130101', 'user2', 124),
('20130101', 'user3', 125),
('20130102', 'user1', 223),
('20130102', 'user3', 223),
('20130103', 'user2', 323);
create table colours (name varchar(10), colour_name varchar(10));
insert colours values
('user1', 'blue'),
('user2', 'green'),
('user3', 'brown');
Consulta :
DECLARE @scols nvarchar(max),
@cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX);
select @cols = STUFF((
SELECT ',' + QUOTENAME(C.Name)
from (select distinct name from [History]) C
ORDER BY C.Name
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,'');
select @scols = STUFF((
SELECT ',' + QUOTENAME(Name) + ' AS ' + QUOTENAME(colour_Name)
from (select distinct c.name, x.colour_name
from [History] C
JOIN colours x on x.name = c.name) y
ORDER BY Name
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,'');
set @query = '
SELECT [Date],' + @scols +'
from (
select [Date], Name, Value
from [History]
) x
pivot
(
max(value)
for Name in (' + @cols + ')
) p ';
-- print @query --<< uncomment this line to see the query that gets generated
exec (@query);
| DATE | BLUE | GREEN | BROWN |
-------------------------------------------------------------
| January, 01 2013 00:00:00+0000 | 123 | 124 | 125 |
| January, 02 2013 00:00:00+0000 | 223 | (null) | 223 |
| January, 03 2013 00:00:00+0000 | (null) | 323 | (null) |
