How to get table-like query result on SQL Server 2005/8? - sql

Question

I have 3 tables:
users (id, name)
currency (id, name)
accounts (id, user_id, currency_id, amount)
And I want to read the data from accounts and present it in table-like view:
owner currency1 currency2 currency3
1 0 0 0
2 10 20 30
3 0 5 10
Where owner is ID of accounts.owner, currency1,2,3 - (SELECT id FROM currency WHERE name = '1',etc)
I can get such result only for one specific ID:
SELECT
SELECT amount FROM accounts WHERE currency = (SELECT id FROM currency WHERE name = 'currency1') AND owner = #user) AS [currency1],
SELECT amount FROM accounts WHERE currency = (SELECT id FROM currency WHERE name = 'currency2') AND owner = #user) AS [currency2],
SELECT amount FROM accounts WHERE currency = (SELECT id FROM currency WHERE name = 'currency2') AND owner = #user) AS [currency2]
Is it possible to get the same result for every object in users table? Without using Reporing Service, etc.

Answer 1

Use a pivot table and dynamic SQL to retrieve the columns
DECLARE #columns VARCHAR(2000)
SELECT #columns = STUFF(( SELECT DISTINCT TOP 100 PERCENT
'],[' + c.name
FROM currency AS c
ORDER BY '],[' + c.name
FOR XML PATH('')
), 1, 2, '') + ']'
DECLARE #query NVARCHAR(4000)
SET #query = N'SELECT UserName, ' + #columns +
'FROM
(SELECT u.Name AS UserName, c.name AS CurrencyName, a.Amount
FROM Accounts AS a WITH(NOLOCK)
JOIN Users u WITH(NOLOCK) ON a.user_id = u.user_id
JOIN Currency c WITH(NOLOCK) ON a.currency_id = c.currency_id
) p
PIVOT
(
SUM (p.Amount)
FOR p.CurrencyName IN
( '+ #columns +')
) AS pvt
ORDER BY UserName'
EXECUTE(#query)
This was tested in SQL Server 2005

Answer 2

Sounds like you want a Pivot table. It will be difficult to do if you have a varying number of rows in currency, but could still be done by using dynamiclly written sql.
Here's a resource from MSDN that explains how to use the pivot table: http://msdn.microsoft.com/en-us/library/ms177410.aspx
SELECT u.name, [1] AS Currency1, [2] AS Currency2, [3] AS Currency3
FROM
(SELECT u.Name AS UserName, c.Currency_ID, a.Amount
FROM Accounts AS a WITH(NOLOCK)
JOIN Users u WITH(NOLOCK) ON a.user_id = u.user_id
) p
PIVOT
(
SUM (p.Amount)
FOR p.Currency_id IN
( [1], [2], [3] )
) AS pvt
ORDER BY pvt.UserName