How can I get days between two dates in the same column? - mysql

I have table structure like where Loanid is Foreign Key
TranID LOANID TRANSDATE
2 2 2013-05-01
13 2 2013-05-10
14 2 2013-05-15
6 5 2013-05-01
7 5 2013-06-10
8 5 2013-06-14
9 5 2013-07-01
10 5 2013-07-10
i need a query to calculate Days between like below .
TranID LOANID TRANSDATE DAYS_BETWEEN
2 2 2013-05-01 9
13 2 2013-05-10 5
14 2 2013-05-15 0
6 5 2013-05-01 41
7 5 2013-06-10 4
8 5 2013-06-14 17
9 5 2013-07-01 9
10 5 2013-07-10 0

Possibly a self join, using MIN to get the next date.
SELECT t1.tranid,
t1.loanid,
t1.transdate
DATEDIFF(IFNULL(MIN(t2.transdate), t1.transdate), t1.transdate) AS days
FROM some_table t1
LEFT OUTER JOIN some_table t2
ON t1.loanid = t2.loan_id
AND t1.transdate < t2.transdate
GROUP BY t1.tranid,
t1.loanid,
t1.transdate

Related

calculating the average of marks from the beginning to this record

i have a table named test with the below structure like this
id mark join_id
1 5 1
2 4 1
3 9 1
4 5 2
5 7 2
6 12 2
i want to write a query that can get me the average of the marks from the beginning record to this record with the desired result as below
id mark join_id avg_of_previous_marks
1 5 1 5
2 4 1 4.5
3 9 1 6
4 5 2 5.75
5 7 2 6
6 12 2 7
i wrote this query but it doesn't seem to work correctly
SELECT test.id, test.mark, test.join_id, test_avg.avg_of_previous_marks FROM test
LEFT JOIN (SELECT id, join_id, AVG(mark) as avg_of_previous_marks FROM test GROUP BY
join_id) test_avg
ON test_avg.join_id = test.join_id AND test_avg.id <= test.id
and it gives this resault
id mark join_id avg_of_previous_marks
1 5 1 6
2 4 1 6
3 9 1 6
4 5 2 8
5 7 2 8
6 12 2 8
Its a simple running total that you need.
select id,mark,join_id, avg(mark) over (order by id) avg_of_previous_marks from test_avg ;
fiddle here

how to generate student attendance percentage per course, when they have specific day in a week

hi guys i really newbie in sql, i need help to generate percentage of attendance, here is the table:
Table Schedule
Schedule_ID Course_ID Lecture_ID Start_Date End_Date Course_Days
1 1 11 2019-09-09 2019-12-08 2,4,6
2 3 4 2019-09-09 2019-12-08 3,4
3 4 13 2019-09-09 2019-12-08 2,5
4 5 28 2019-09-09 2019-12-08 3
5 2 56 2020-01-27 2020-04-26 2,4
6 7 1 2020-01-27 2020-04-26 4,5
7 1 11 2020-01-27 2020-04-26 2,4,6
8 7 22 2020-01-27 2020-04-26 2,3
9 8 56 2020-01-27 2020-04-26 5
10 3 37 2020-01-27 2020-04-26 5,6
Reference of days of week used in this data.
1: Sunday, 2:Monday, 3:Tuesday, 4:Wednesday, 5:Thursday, 6:Friday, 7:Saturday
Table course_attendance
ID STUDENT_ID SCHEDULE_ID ATTEND_DT
1 1 2 2019-09-10
2 1 2 2019-09-11
3 1 2 2019-09-17
4 1 2 2019-09-18
......
46 2 1 2019-12-02
47 2 1 2019-09-11
48 2 1 2019-09-18
49 2 1 2019-09-25
50 2 1 2019-10-09
51 2 1 2019-10-16
....
111 6 1 2019-09-23
112 6 1 2019-09-30
113 6 1 2019-10-07
114 6 1 2019-10-14
table student
ID NAME
1 Jonny
2 Cecilia
3 Frank
4 Jones
5 Don
6 Harry
i need to show up like this :
STUDENT_ID NAME Course_ID Attendance rate
1 Jonny 1 82%
2 Cecilia 1 30%
3 Frank 3 100%
4 Jones 2 100%
5 Don 2 25%
6 Harry 4 40%
EDIT this my last step to get percentage:
result:
with main as (
select ca.STUDENT_ID,
ca.SCHEDULE_ID,
s.COURSE_ID,
co.NAME as course_name,
st.NAME,
count(ca.ID) as total_attendance,
((CHAR_LENGTH(s.COURSE_DAYS) - CHAR_LENGTH(REPLACE(s.COURSE_DAYS , ',', '')) + 1) * 13) as attendance_needed
from univ.course_attendance ca
left join univ.schedule s on ca.SCHEDULE_ID = s.ID
left join univ.student st on ca.SCHEDULE_ID = st.ID
left join univ.course co on ca.SCHEDULE_ID = co.ID
group by ca.STUDENT_ID, ca.SCHEDULE_ID
)
select *,total_attendance/attendance_needed as attendance_percentage
from main
order by 1,2;
This can be done following three steps.
Step 1: Calculate the total number of days a particular course of a schedule has. It's a good thing the start_date is always on Monday and the end_date is always on Sunday, which makes the week complete and saves some trouble. By calculating the total number of weeks a course go through and the number of days a week has for that course, we can get the total number of days a particular course of a schedule has.
Step 2:Calculate the total number of days a student for a schedule. This is done fairly easily. Note: As the majority part of the table has been skipped and the OP has yet to provide the complete data set, I could only have 14 existing rows provided.
Step 3: Calculate the percentage for the attendance using the result from the above two steps and get other required columns.
Here is the complete statement I wrote and tested in workbench:
select t2.student_id as student_id,`name`,course_id, (t2.total_attendance/t1.total_course_days)*100 as attendance_rate
from (select schedule_id,course_id,
length(replace(course_days,',',''))*(week(end_date)-week(start_date)) as total_course_days
from Schedule) t1
JOIN
(select count(attend_dt) as total_attendance,student_id,schedule_id
from course_attendance group by student_id, schedule_id) t2
ON t1.schedule_id=t2.schedule_id
JOIN
student s
ON t2.student_id=s.id;
Here is the result set ( the attendance_rate is not nice due to the abridged course_attendance table):
student_id, name, course_id, attendance_rate
2, Cecilia, 1, 15.3846
6, Harry, 1, 10.2564
1, Jonny, 3, 15.3846

Ranking of the affiliates with most commissions from database

The table "commissions" is of this form:
affiliate referral amount date
3 2 15 2016-08-27
1 22 10 2016-08-29
4 45 5 2016-09-06
1 33 9 2016-09-08
3 17 4 2016-09-11
2 33 10 2016-09-16
1 9 7 2016-09-26
3 17 9 2016-09-26
2 69 10 2016-09-30
1 21 7 2016-10-01
4 55 2 2016-10-06
I need to find out the ranking of the affiliates with most commissions month to month.
I have tried:
SELECT affiliate, SUM(amount) as amount
FROM commissions
GROUP BY affiliate, YEAR(date), MONTH(date)
But unfortunately it is not throwing the desired results.
Please help.

SQL: Split Dataset into two columns

I have a table like this:
id c_id time value
1 4 1 12
2 4 2 5
3 4 3 6
4 4 4 48
5 4 5 1
6 4 6 121
7 5 1 121
8 5 2 321
9 5 3 2
10 5 4 1
11 5 5 54
12 5 6 4546
13 5 7 78
14 5 8 784
15 5 9 1
Now I want a table like this with a SELECT command:
time1 value1 time2 value2
1 12 1 121
2 5 2 321
3 6 3 2
4 48 4 1
5 1 5 54
6 121 6 4546
0 0 7 78
0 0 8 784
0 0 9 1
time1 and value1 is from the data with c_id=4,
time2 and value2 is from the data with c_id=5
Is it possible to create a SELECT command to do that?
I hope you can help
Yiu can use an inner join
select a.time as time1, a.value as value1, b.time as time2, b.value as value2
from my_table as a
inner join my_table as b on a.time = b.time
and a.c_id= 4
and b.c_id= 5;

mySQL AVG a field with a range of dates on the same table

I have a table
date d_id r_id p_id q_sold onhand
2012-10-10 5 1 3025 3 10
2012-10-10 5 1 3022 12 20
2012-10-10 5 1 3023 15 33
2012-10-11 5 1 3025 3 10
2012-10-11 5 1 3022 12 20
2012-10-11 5 1 3023 15 33
2012-10-12 5 1 3025 3 10
2012-10-12 5 1 3022 12 20
2012-10-12 5 1 3023 15 33
2012-10-13 5 1 3025 3 10
2012-10-13 5 1 3022 12 20
2012-10-13 5 1 3023 15 33
2012-10-14 5 1 3025 3 10
2012-10-14 5 1 3022 12 10
2012-10-14 5 1 3023 15 33
2012-10-15 5 1 3025 3 5
2012-10-15 5 1 3022 12 5
2012-10-15 5 1 3023 15 33
I would like to get the result of the q_sold divided by average of the onhand over a 5 day period, while displaying the other data for a specific date like the 2012-10-15.
I create a query
set #stdate = '2012-10-10';
set #endate = '2012-10-15';
SELECT date, d_id,r_id,p_id,q_sold,onhand,qty_sold/AVG(qty_onhand)
FROM stp_vwsales_info_tots
WHERE date BETWEEN #stdate and #endate and d_id=5
GROUP BY d_id,r_id,p_id
But the result being showed is incorrect, it displays the data for the 2012-10-10 instead of 2010-10-15
date d_id r_id p_id q_sold onhand avg
2012-10-10 5 1 3022 12 20 0.7579
2012-10-10 5 1 3023 15 33 0.4545
2012-10-10 5 1 3025 3 10 0.3273
Can anyone help?
Use your #stdate and #endate as DATE(#stdate/#endate) or DATE_FORMAT(#stdate/#endate,'%Y-%m-%d') otherwise you have to convert #stdate/#endate from string to date through MySQL
i think what your looking for is something called a simple moving average.
to calculate this you'll need to use an inline subquery - so performance won't be the best.
assuming you want to calculate the average over the previous 5 day period, try something like this:
SELECT
date, d_id, r_id, p_id, q_sold, onhand,
( SELECT q_sold/AVG(t2.onhand)
FROM stp_vwsales_info_tots AS t2
WHERE p_id=t1.p_id AND DATEDIFF(t1.date, t2.date) BETWEEN 0 AND 4
) AS 'moving_avg'
FROM stp_vwsales_info_tots AS t1
GROUP BY t1.p_id,t1.date
order by t1.date;