Insert subquery date according to day - date

Question

I would like to insert subquery a date based on it day. Plus, each date can only be used four times. Once it reached fourth times, the fifth value will use another date of same day. In other word, use date of Monday of next week. Example, Monday with 6 JUNE 2016 to Monday with 13 JUNE 2016 (you may check the calendar).
I have a query of getting a list of date based on presentationdatestart and presentationdateend from presentation table:
select a.presentationid,
a.presentationday,
to_char (a.presentationdatestart + delta, 'DD-MM-YYYY', 'NLS_CALENDAR=GREGORIAN') list_date
from presentation a,
(select level - 1 as delta
from dual
connect by level - 1 <= (select max (presentationdateend - presentationdatestart)
from presentation))
where a.presentationdatestart + delta <= a.presentationdateend
and a.presentationday = to_char(a.presentationdatestart + delta, 'fmDay')
order by a.presentationdatestart + delta,
a.presentationid; --IMPORTANT!!!--
For example,
presentationday presentationdatestart presentationdateend
Monday 01-05-2016 04-06-2016
Tuesday 01-05-2016 04-06-2016
Wednesday 01-05-2016 04-06-2016
Thursday 01-05-2016 04-06-2016
The query result will list all possible dates between 01-05-2016 until 04-06-2016:
Monday 02-05-2016
Tuesday 03-05-2016
Wednesday 04-05-2016
Thursday 05-05-2016
....
Monday 30-05-2016
Tuesday 31-05-2016
Wednesday 01-06-2016
Thursday 02-06-2016 (20 rows)
This is my INSERT query :
insert into CSP600_SCHEDULE (studentID,
studentName,
projectTitle,
supervisorID,
supervisorName,
examinerID,
examinerName,
exavailableID,
availableday,
availablestart,
availableend,
availabledate)
select '2013816591',
'mong',
'abc',
'1004',
'Sue',
'1002',
'hazlifah',
2,
'Monday', //BASED ON THIS DAY
'12:00:00',
'2:00:00',
to_char (a.presentationdatestart + delta, 'DD-MM-YYYY', 'NLS_CALENDAR=GREGORIAN') list_date //FOR AVAILABLEDATE
from presentation a,
(select level - 1 as delta
from dual
connect by level - 1 <= (select max (presentationdateend - presentationdatestart)
from presentation))
where a.presentationdatestart + delta <= a.presentationdateend
and a.presentationday = to_char(a.presentationdatestart + delta, 'fmDay')
order by a.presentationdatestart + delta,
a.presentationid;
This query successfully added 20 rows because all possible dates were 20 rows. I would like modify the query to be able to insert based on availableDay and each date can only be used four times for each different studentID.
Possible outcome in CSP600_SCHEDULE (I am removing unrelated columns to ease readability):
StudentID StudentName availableDay availableDate
2013 abc Monday 01-05-2016
2014 def Monday 01-05-2016
2015 ghi Monday 01-05-2016
2016 klm Monday 01-05-2016
2010 nop Tuesday 02-05-2016
2017 qrs Tuesday 02-05-2016
2018 tuv Tuesday 02-05-2016
2019 wxy Tuesday 02-05-2016
.....
2039 rrr Monday 09-05-2016
.....
You may check the calendar :)

Answer 1

I think what you're asking for is to list your students and then batch them up in groups of 4 - each batch is then allocated to a date. Is that right?
In which case something like this should work (I'm using a list of tables as the student names just so I don't need to insert any data into a custom table) :
WITH students AS
(SELECT table_name
FROM all_tables
WHERE rownum < 100
)
SELECT
table_name
,SYSDATE + (CEIL(rownum/4) -1)
FROM
students
;
I hope that helps you
...okay, following your comments, I think this might be a better solution :
WITH students AS
(SELECT table_name student_name
FROM all_tables
WHERE rownum < 100
)
, dates AS
(SELECT TRUNC(sysdate) appointment_date from dual UNION
SELECT TRUNC(sysdate+2) from dual UNION
SELECT TRUNC(sysdate+4) from dual UNION
SELECT TRUNC(sysdate+6) from dual UNION
SELECT TRUNC(sysdate+8) from dual UNION
SELECT TRUNC(sysdate+10) from dual UNION
SELECT TRUNC(sysdate+12) from dual UNION
SELECT TRUNC(sysdate+14) from dual
)
SELECT
s.student_name
,d.appointment_date
FROM
--get a list of students each with a sequential row number, ordered by student name
(SELECT
student_name
,ROW_NUMBER() OVER (ORDER BY student_name) rn
FROM students
) s
--get a list of available dates with a sequential row number, ordered by date
,(SELECT
appointment_date
,ROW_NUMBER() OVER (ORDER BY appointment_date) rn
FROM dates
) d
WHERE 1=1
--allocate the first four students to date rownumber1, next four students to date rownumber 2...
AND CEIL(s.rn/4) = d.rn
;