How do I select a variable row in SQL Server?

Question

Frustratingly, I\'m working with a table where the row name should be a value. How can I select that row in SQL Server based on a value? I\'m aiming at something that looks like

Answer 1

What a bad design :( Anyway, you can do what you want in a number of ways and one way is to use UNPIVOT:

declare @t1 table (item varchar(10),    year int,      model varchar(10));
insert @t1 (item,year,model) values 
('xx',2001,'MODELC'),
('yy',2002,'MODELA'),
('zz',2002,'MODELD');

declare @t2 table (year int, modela int, modelb int, modelc int, modeld int);

insert @t2 (YEAR,   MODELA,    MODELB,    MODELC,   MODELD) values
(2000,100 ,101 ,102 ,103 ),
(2001,205 ,206 ,250 ,300 ),
(2002,1000,1200,1500,1700);

with up as
( 
  select year, v, model
  from 
  (select YEAR, MODELA, MODELB, MODELC, MODELD from @t2) p
   unpivot  
   (v for model in (MODELA,    MODELB,    MODELC,   MODELD)) as unp
)
select t1.*, up.v from @t1 t1 inner join up on t1.year = up.year and t1.model = up.model;

Answer 2

This can be done with standard SQL, albeit a bit ugly:

select i.item, 
       i.year, 
       i.model,
       case i.model 
           when 'MODELA' then p.MODELA 
           when 'MODELB' then p.MODELB 
           when 'MODELC' then p.MODELC 
           when 'MODELD' then p.MODELD 
       end as price
from Items i INNER JOIN Pricing p ON p.year = i.year

Rextexter demo

Answer 3

DEMO

use unpivot and then join to your item table.

WITH cte as (
    SELECT [Year], [Model], [Price]
    FROM (SELECT [Year], [MODELA], [MODELB], [MODELC], [MODELD]
          FROM pricing) p
    UNPIVOT 
        ([Price] FOR [Model] IN 
                     ([MODELA], [MODELB], [MODELC], [MODELD])
        ) as unpvt
) 
SELECT i.*, c.price
FROM cte c
JOIN items i 
  ON c.[Year] = i.[Year]
 AND c.[Model] = i.[model]

OUTPUT