How to DISPLAY horizontal data into vertical columns in SQL? - sql-server

Question

I have tables Employees, Documents, Transactions, from_to table.
Employee can send a document to other employee and send a copy of the document to other employee.
data will be displayed in transaction table as follow:
TransId - Document Id - EmployeeId - from_toId
1 1 5 1 (From)
2 1 6 2 (To)
3 1 10 2 (CC)
Now; I want the data above to be displayed as follow:
DocId From To CC
1 Jo(5) Fo(6) Do(10)
I know that we need something to do with "Pivot Table". BUT I DON'T KNOW HOW.
Waiting for your feedback.

Answer 1

I have a solution with a Cursor which is dynamic:
CREATE TABLE #PRERESULT(
[TransId] int,
DocumentID int ,
EmployeeId int ,
from_toId [nvarchar](10)
)
INSERT INTO #PRERESULT ([TransId],DocumentID,EmployeeId,from_toId)
VALUES
(1,1,5,'1 (From)'),
(2,1,6,'2 (To)'),
(3,1,10,'2 (CC)')
CREATE TABLE #RESULT (
DocID int,
[From] nvarchar(15),
[To] nvarchar(15),
CC nvarchar(15))
INSERT INTO #RESULT (DocID)
SELECT DocumentID
FROM #PRERESULT
GROUP BY DocumentID
DECLARE #Documentid int,#Employee int, #Alias nvarchar(10),#SQL nvarchar(250)
DECLARE C_FromTo CURSOR
FOR
SELECT DocumentID,EmployeeID
FROM #PRERESULT
OPEN C_FromTo
FETCH NEXT FROM C_FromTo INTO #Documentid, #Employee
While (##Fetch_status = 0)
BEGIN
SET #Alias = (SELECT SUBSTRING(from_toId,PATINDEX('%(%',from_toId)+1,(LEN(from_toId)-PATINDEX('%(%',from_toId)-1)) FROM #PRERESULT WHERE #Employee = EmployeeId)
SET #SQL = 'UPDATE #RESULT
SET ['+#Alias+'] = '+Convert(nvarchar(50),#Employee)+'
WHERE '+Convert(nvarchar(50),#Documentid)+' = DocID'
EXEC (#SQL)
FETCH NEXT FROM C_FromTo INTO #Documentid, #Employee
END
CLOSE C_FromTo
DEALLOCATE C_FromTO
SELECT * FROM #RESULT
DROP TABLE #PRERESULT
DROP TABLE #RESULT
Gives you this:
DocID |From |To |CC
1 |5 |6 |10
Hope this will help you
Have a nice day & Greets from Switzerland
Etienne

Answer 2

I think this reflects your table, although I am using names instead of IDs for the last two columns:
CREATE TABLE [dbo].[Transaction](
[TransId] [int] NOT NULL,
[DocId] [int] NOT NULL,
[EmpId] [nvarchar](10) NOT NULL,
[FromToId] [nchar](10) NOT NULL
) ON [PRIMARY]
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(1,1,'Jo','From')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(2,1,'Fo','To')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(3,1,'Do','CC')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(4,2,'Jo','From')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(5,2,'Bo','To')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(6,2,'Zo','CC')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(7,3,'Bo','From')
INSERT INTO [Transaction] ([TransId],[DocId],[EmpId],[FromToId])VALUES(8,3,'Go','To')
Then this query will give you the results you requested:
SELECT DISTINCT
t.DocId
,x.[From]
,y.[To]
,z.Cc
FROM [Transaction] t
LEFT JOIN
(
SELECT DocId
,CASE WHEN FromToId = 'From' THEN EmpId END AS [From]
FROM [Transaction]
WHERE CASE WHEN FromToId = 'From' THEN EmpId END IS NOT NULL
) x ON t.DocId = x.DocId
LEFT JOIN
(
SELECT DocId
,CASE WHEN FromToId = 'To' THEN EmpId END AS [To]
FROM [Transaction]
WHERE CASE WHEN FromToId = 'To' THEN EmpId END IS NOT NULL
) y ON t.DocId = y.DocId
LEFT JOIN
(
SELECT DocId
,CASE WHEN FromToId = 'CC' THEN EmpId END AS [Cc]
FROM [Transaction]
WHERE CASE WHEN FromToId = 'Cc' THEN EmpId END IS NOT NULL
) z ON t.DocId = z.DocId
DocId From To Cc
1 Jo Fo Do
2 Jo Bo Zo
3 Bo Go NULL