PIVOT and UNPIVOT in SQL Server

Transforming rows to columns (PIVOT/CROSS TAB) and columns to rows is (UNPIVOT). Reverse operation of PIVOT is UNPIVOT.

Actual Table :

StudentName	Marks	Grade
A	10	I
B	20	II
C	40	IV
D	30	III

Select studentname, [I], [II], [III], [IV]
 from
( Select grade, studentname, marks from tbl_student) as sourcetable
Pivot (  avg(marks) for grade in ([I],[II],[III],[IV)) as pivotable order by IV desc,III desc,II desc,I desc

PIVOT Result Table :

StudentName	I	II	III	IV
A	10
B		20
C				40
D			30

Actual Table :

StudentName	I	II	III	IV
A	10
B		20
C				40
D			30

select studentname,Marks,Grade

from tbl_stdmarksdata

unpivot

(Marks for Grade in (I,II,III,IV) ) as tblunpvt

UNPIVOT Result Table :

StudentName	Marks	Grade
A	10	I
B	20	II
C	40	IV
D	30	III