Group report together, possibly with SQL? - sql

Question

I have a table called Register which contains the following fields:
Date, AMPM, Mark.
A day can have two records for a day. Its fairly easy to select and display all the records in a list ordered by date ascending.
What I would like to do is display the data as a grid. Something along the lines of.
| Mon | Tues| Wed| Thurs| Fri | Sat
9/8/2014 | /\ | /P | /\ | L | /\ | /
Have a week beginning and then group the 5 together. I'm not even sure sql is the best option for this, but the groupby commands seem to suggest it may be able to do this.
The Data structure is as follows.
Date, AMPM, Mark
9/8/2014, AM, /
9/8/2014, PM, \
9/9/2014, AM, /
9/9/2014, PM, P
9,10,2014, AM, /
9,10,2014, PM, \
9,11,2014, PM, L
....
The mark field can contain a number of letters. P for instance means they are participating in a sporting activity. L means they were late.
Does anyone have any resources they can point me towards the right direction that would be helpful. I'm not even sure what this type of report is called and whether I should be using SQL or javascript to group this data in a presentable format. The / \ represents AM and the a PM.

Answer 1

The following query would get you the desired result. If you need Sunday also, you'll have to add a small condition to test for when days_after_last_Monday = 6 in the CASE statement.
select
last_Monday Week_Starting,
max(
case
when days_after_last_Monday = 0 then mark
else null
end) Mon, --if the # of days between previous Monday and reg_date is zero, then get the according mark
max(
case
when days_after_last_Monday = 1 then mark
else null
end) Tues,
max(
case
when days_after_last_Monday = 2 then mark
else null
end) Wed,
max(
case
when days_after_last_Monday = 3 then mark
else null
end) Thurs,
max(
case
when days_after_last_Monday = 4 then mark
else null
end) Fri,
max(
case
when days_after_last_Monday = 5 then mark
else null
end) Sat
from
(
select
reg_date,
last_Monday,
julianday(reg_date) - julianday(last_Monday) as days_after_last_monday, --determine the number of days between previous Monday and reg_date
mark
from
(
select
reg_date,
case
when cast (strftime('%w', reg_date) as integer) = 1 then date(reg_date, 'weekday 1')
else date(reg_date, 'weekday 1', '-7 days')
end last_monday, --determine the date of previous Monday
mark
from
(
select
reg_date,
group_concat(mark, '') mark --concatenate am and pm marks for each reg_date
from
(
SELECT
reg_date,
ampm,
mark
FROM register
order by reg_date, ampm --order by ampm so that am rows are selected before pm
)
group by reg_date
)
)
)
group by last_Monday
order by last_Monday;
SQL Fiddle demo