SQL Server 2008 CrossTab equivalent - sql

Question

Afternoon Guys n Girls.
Using SQL SERVER 2008.
I have a table called userModList. Its contains fields, "USERID"(int), "ModuleID"(int), and "Passed"(bin).
example data;
USERID ModuleID Passed
134 12 1
134 10 0
134 18 1
What i would like to display is:
USERID (moduleNum12) (ModuleNum10) (ModuleNum18)
134 1 0 1
Now In MS access all you would do is create a cross query, so User ID becomes the row, Module numbers become the Columns and Passed is the values (binary 1 or 0).
I would like to do this server Side in a Stored Procedure, but I have never Attempted cross tabbing data.
Also The moduleID is dynamic meaning there may be 3 modules for a user or 17. So it needs to be dynamic, not sure if this makes a big difference?
Anyway some help on this would be great, ill try and provide some sample code Of what I will try, But as it stands I'm stuck as to where to start.
many thanks guys!

Answer 1

There are a few different ways that you can do this in SQL Server you can use the PIVOT function:
select userid,
[12] moduleNum12,
[10] moduleNum10,
[18] moduleNum18
from
(
select userid, moduleid, cast(passed as int) passed
from yourtable
) d
pivot
(
max(passed)
for moduleId in ([12], [10], [18])
) piv;
See Demo
Or you can use an aggregate function with a CASE expression:
select userid,
max(case when moduleid = 12 then cast(passed as int) end) moduleNum12,
max(case when moduleid = 10 then cast(passed as int) end) moduleNum10,
max(case when moduleid = 18 then cast(passed as int) end) moduleNum18
from yourtable
group by userid;
See Demo.
The above work great if the values are known nut if you have unknown values, then you will need to use dynamic SQL:
DECLARE #cols AS NVARCHAR(MAX),
#colsAlias AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT distinct ',' + QUOTENAME(ModuleID)
from yourtable
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
select #colsAlias = STUFF((SELECT distinct ', ' + QUOTENAME(ModuleID) +' as moduleNum'+cast(ModuleID as varchar(10))
from yourtable
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = 'SELECT userid,' + #colsAlias + '
from
(
select userid, moduleid, cast(passed as int) passed
from yourtable
) d
pivot
(
max(passed)
for moduleid in (' + #cols + ')
) p '
execute(#query)
See Demo