Flera alias, en kolumn?

data    data   data
---------------------
1a      2a     3a

data
---------------------
1a2a3a

data
---------------------
1a
2a
3a

-- DEMOTABLE
DECLARE
	@tab TABLE (rowid int identity(1,1), col1 char(2), col2 char(2), col3 char(2));

-- LOAD DEMOTABLE
WITH
	c(n) AS (SELECT '1' UNION ALL SELECT '2' UNION ALL SELECT '3'),
	d(a) AS (SELECT 'a' UNION ALL SELECT 'b' UNION ALL SELECT 'c' UNION ALL SELECT 'd' UNION ALL SELECT 'e' UNION ALL SELECT 'f'),
	r(n,r, na) AS (SELECT c.n, ROW_NUMBER() OVER(PARTITION BY c.n ORDER BY d.a), c.n + d.a FROM c CROSS JOIN d)
INSERT INTO @tab(col1, col2, col3)
SELECT 
	c1.na, c2.na, c3.na 
FROM r c1 INNER JOIN r c2 ON c1.r = c2.r INNER JOIN r c3 ON c1.r = c3.r
WHERE c1.n = '1' AND c2.n = '2' AND c3.n = '3';

-- VIEW DEMOTABLE
SELECT * from @tab

-- SOLUTION
SELECT rowid, data FROM @tab
UNPIVOT(
data FOR col IN([col1],[col2],[col3])
)x
/*
-- YOUR QUERY
SELECT data FROM accounts
UNPIVOT(
data FOR col IN([user],[users],[user2])
*/