SQL Unpivot multiple columns Data - sql

Question

I am using SQL server 2008 and I am trying to unpivot the data. Here is the SQL code that I am using,
CREATE TABLE #pvt1 (VendorID int, Sa int, Emp1 int,Sa1 int,Emp2 int)
GO
INSERT INTO #pvt1 VALUES (1,2,4,3,9);
GO
--Unpivot the table.
SELECT distinct VendorID,Orders,Orders1
FROM
(SELECT VendorID, Emp1, Sa,Emp2,Sa1
FROM #pvt1 ) p
UNPIVOT
(Orders FOR Emp IN
(Emp1,Emp2)
)AS unpvt
UNPIVOT
(Orders1 FOR Emp1 IN
(Sa,Sa1)
)AS unpvt1;
GO
And Here is the result of the above code.
VendorID Orders Orders1
1 4 2
1 4 3
1 9 2
1 9 3
But I want my Output to be the way indicated below
VendorID Orders Orders1
1 4 2
1 9 3
The relationship from the above code is 2 is related to 4, and 3 is related to 9.
How can I achieve this?

Answer 1

An easier way to unpivot the data would be to use a CROSS APPLY to unpivot the columns in pairs:
select vendorid, orders, orders1
from pvt1
cross apply
(
select emp1, sa union all
select emp2, sa1
) c (orders, orders1);
See SQL Fiddle with Demo. Or you can use CROSS APPLY with the VALUES clause if you don't want to use the UNION ALL:
select vendorid, orders, orders1
from pvt1
cross apply
(
values
(emp1, sa),
(emp2, sa1)
) c (orders, orders1);
See SQL Fiddle with Demo

Answer 2

The answer by Taryn is indeed super useful, and I'd like to expand one aspect of it.
If you have a very un-normalized table like this, with multiple sets of columns for e.g. 4 quarters or 12 months:
+-------+------+------+------+------+------+------+-------+------+
| cYear | foo1 | foo2 | foo3 | foo4 | bar1 | bar2 | bar3 | bar4 |
+-------+------+------+------+------+------+------+-------+------+
| 2020 | 42 | 888 | 0 | 33 | one | two | three | four |
+-------+------+------+------+------+------+------+-------+------+
Then the CROSS APPLY method is easy to write and understand, when you got the hang of it. For the numbered column, use constant values.
SELECT
cYear,
cQuarter,
foo,
bar
FROM temp
CROSS APPLY
(
VALUES
(1, foo1, bar1),
(2, foo2, bar2),
(3, foo3, bar3),
(4, foo4, bar4)
) c (cQuarter, foo, bar)
Result:
+-------+----------+-----+-------+
| cYear | cQuarter | foo | bar |
+-------+----------+-----+-------+
| 2020 | 1 | 42 | one |
| 2020 | 2 | 888 | two |
| 2020 | 3 | 0 | three |
| 2020 | 4 | 33 | four |
+-------+----------+-----+-------+
SQL Fiddle

Answer 3

I needed composit key AND skip extras row in case when data is missing (NULLs). For ex. when x2 and y2 are possible replacement vendor and price
WITH pvt AS (SELECT * FROM (VALUES
( 1, 6, 11, 111, 12, 13, 122, 133),
( 2, 6, 21, 211, 22, 23, 222, 233),
( 3, 6, 31, 311, 32, 33, 322, 333),
( 5, 4, 41, 411, 42, NULL, 422, NULL),
( 6, 4, 51, 511, 52, NULL, 522, NULL))
s( id, s, a, b, x1, x2, y1, y2)
)
-- SELECT * FROM pvt
SELECT CONCAT('xy_',s,'_', id, postfix) as comp_id, a, b, x, y
FROM pvt
CROSS APPLY
(
VALUES
(NULL, x1, y1),
('_ext', x2, y2)
) c (postfix, x, y)
WHERE x IS NOT NULL
produces
comp_id a b x y
-------------------------------- ----------- ----------- ----------- -----------
xy_6_1 11 111 12 122
xy_6_1_ext 11 111 13 133
xy_6_2 21 211 22 222
xy_6_2_ext 21 211 23 233
xy_6_3 31 311 32 322
xy_6_3_ext 31 311 33 333
xy_4_5 41 411 42 422
xy_4_6 51 511 52 522
(8 rows affected)
from:
id s a b x1 x2 y1 y2
----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------
1 6 11 111 12 13 122 133
2 6 21 211 22 23 222 233
3 6 31 311 32 33 322 333
5 4 41 411 42 NULL 422 NULL
6 4 51 511 52 NULL 522 NULL
(5 rows affected)