How to pivot rows into columns (custom pivoting)

Question

I have a Sql Database table similar to the following:

Day   Period    Subject

Mon   1         Ch
Mon   2         Ph
Mon   3         Mth
Mon   4         CS
M         


        

Answer 1

You could probably do it with the PIVOT function, but I prefer the old school method:

SELECT
    dy,
    MAX(CASE WHEN period = 1 THEN subj ELSE NULL END) AS P1,
    MAX(CASE WHEN period = 2 THEN subj ELSE NULL END) AS P2,
    MAX(CASE WHEN period = 3 THEN subj ELSE NULL END) AS P3,
    MAX(CASE WHEN period = 4 THEN subj ELSE NULL END) AS P4,
    MAX(CASE WHEN period = 5 THEN subj ELSE NULL END) AS P5,
    MAX(CASE WHEN period = 6 THEN subj ELSE NULL END) AS P6,
    MAX(CASE WHEN period = 7 THEN subj ELSE NULL END) AS P7
FROM
    Classes
GROUP BY
    dy
ORDER BY
    CASE dy
        WHEN 'Mon' THEN 1
        WHEN 'Tue' THEN 2
        WHEN 'Wed' THEN 3
        WHEN 'Thu' THEN 4
        WHEN 'Fri' THEN 5
        WHEN 'Sat' THEN 6
        WHEN 'Sun' THEN 7
        ELSE 8
    END

• I changed some column names to avoid reserved words