Combine Static Columns with Dynamic Columns in SQL SERVER 2008 - sql

Question

I have a table SchoolStudent with three columns and the following values
Now, for a student we can have dynamic columns which are stored in a table with values as:
I want a query where i can club static fields as well as dynamic fields in a single SQL Query. I tried using Pivot but was not successful. Please suggest on how to accomplish this. I am basically doing it so that on frontend i have one resultset which can be searched thru.
So query should be:
Select
StudentID, FirstName, Address, MotherName,
MotherEmail, MotherOccupation, Mother Salary,
FacebookProfileName, VehicleRegNo
from SchoolStudent
Inner Join
(Logic to convert rows to columns)

Answer 1

Since you have dynamic columns, then you will need to use dynamic SQL to generate the result that you want. This query will generate the list of columns in the second table and PIVOT them to then be joined to the SchoolStudent to get the other columns:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT distinct ',' + QUOTENAME(DynamicColumnName)
from StudentDetails
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = '
select s.studentid,
s.firstname,
s.address,
d.*
from SchoolStudent s
inner join
(
SELECT studentId,' + #cols + '
from
(
select studentId, dynamiccolumnname,
dynamiccolumnvalue
from StudentDetails
) x
pivot
(
max(dynamiccolumnvalue)
for dynamiccolumnname in (' + #cols + ')
) p
) d
on s.StudentId = d.StudentId'
execute(#query);
See SQL Fiddle with Demo. This query gives the result:
| STUDENTID | FIRSTNAME | ADDRESS | FACEBOOK PROFILE NAME | MOTHER EMAIL | MOTHER NAME | MOTHER OCCUPATION | MOTHER SALARY | VEHICLE REG NO |
-----------------------------------------------------------------------------------------------------------------------------------------------
| 4 | admin | efewfwfew | ross | ram#ram.com | ram#ram.com | ram#ram.com | ram#ram.com | UP 14 as |

Answer 2

You could use sub query format like this:
SELECT t1.StudentID,
t1.FirstName,
t1.Address,
(SELECT t2.DynamicColumnValue FROM table2 t2 WHERE t2.StudentID = t1.StudentID AND t2.DynamicColumnName = 'Mother Name') AS 'MotherName',
(SELECT t2.DynamicColumnValue FROM table2 t2 WHERE t2.StudentID = t1.StudentID AND t2.DynamicColumnName = 'Mother Email') AS 'MotherEmail'
FROM Table1 t1
or you could use inner join format like this:
SELECT t1.StudentID,
t1.FirstName,
t1.Address,
t2.DynamicColumnValue AS 'MotherName'
t3.DynamicColumnValue AS 'MotherEmail'
FROM Table1 t1
INNER JOIN Table2 t2 ON t1.StudentID = t2.StudentID AND t2.DynamicColumnName = 'Mother Name'
INNER JOIN Table2 t3 ON t1.StudentID = t3.StudentID AND t2.DynamicColumnName = 'Mother Email'

Answer 3

With some dynamic sql, you can do this:
DECLARE #cols NVARCHAR(2000)
SELECT #cols = STUFF((SELECT DISTINCT '],[' + DynamicColumnName FROM DynamicValues ORDER BY '],[' + DynamicColumnName FOR XML PATH('')), 1, 2, '') + ']'
DECLARE #query NVARCHAR(4000);
SET #query = N'select s.StudentID, s.FirstName, s.Address,'+#cols+' from SchoolStudent s
join
(
select * from DynamicValues
pivot (Max(DynamicColumnValue) for DynamicColumnName in ('+#cols+')) as pvt
) as b on b.StudentID=s.StudentID'
EXECUTE(#query)