Erland Sommarskog (9/12/2013)

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Blimey? Must be some lingo local to Port Moresby.

Any way, since I don't think that there was a post with CROSS JOIN for unpivotting, here is an example, taken from another thread. When looking at the query plans, the CROSS APPLY solution looks better, but I would need more data to test. I would like to point out, though, that the solution with CROSS JOIN has the distinct advantage of being fully portable across platforms. (Hm, not all engines may support the VALUES clause, but it's easliy replaced with SELECT UNION ALL.)

Create Table #sample

( Name Varchar(100) PRIMARY KEY,

Mark1 int,

Mark2 int,

Mark3 int)

insert into #sample values ('Vignesh',100,59,95)

insert into #sample values ('ram',23,45,33)

insert into #sample values ('kumar',58,12,15)

insert into #sample values ('umar',15,25,98)

go

SELECT s.Name, CASE n.n WHEN 1 THEN s.Mark1

WHEN 2 THEN s.Mark2

WHEN 3 THEN s.Mark3

END AS Mark,

CASE n.n WHEN 1 THEN 'Mark1'

WHEN 2 THEN 'Mark2'

WHEN 3 THEN 'Mark3'

END AS MarkName

FROM #sample s

CROSS JOIN (VALUES (1), (2), (3)) AS n(n)

ORDER BY s.Name, n.n

go

SELECT s.Name, M.Mark, M.name

FROM #sample s

CROSS APPLY (VALUES (1, s.Mark1, 'Mark1'), (2, s.Mark2, 'Mark2'), (3, s.Mark1, 'Mark3')) AS M(n, Mark, name)

ORDER BY s.Name, M.n

go

DROP TABLE #sample

Note that here I have added a column n to the CROSS APPLY table to make that query fully equivalent to the CROSS JOIN solution, but in the APPLY solution you don't need n if you don't care about order, whereas it's a driving column in the CROSS JOIN solution.

As for UNPIVOT - I have never been able to learn it, the same with PIVOT.