I have two tables...
MODULES ENROLMENTS
GroupNo StudentNo
Title GroupNo
Tutor CourseworkMark
DayNo ExamMark
Time
Room
Semester
I wish to create a view that displays the average mark achieved in coursework and exam for each module and also a count of the number of students who achieved >70, 60-69, 50-59, 40-49 and <40. Is this possible?
I have the average marks worked out with...
SELECT Title,
AVG(CourseworkMark) AS AverageCoursework,
AVG(ExamMark) AS AverageExam
FROM tblModules INNER JOIN tblEnrolments
ON tblModules.GroupNo = tblEnrolments.GroupNo
GROUP BY Title;
You can use a SUMmed CASE expression to do this;
SELECT Title,
AVG(CourseworkMark) AS AverageCoursework,
AVG(ExamMark) AS AverageExam,
SUM(CASE WHEN CourseworkMark > 70 THEN 1 ELSE 0 END) AS CourseworkMarkOver70,
SUM(CASE WHEN CourseworkMark BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS CourseworkMarkOver60To69,
SUM(CASE WHEN CourseworkMark BETWEEN 50 and 59 THEN 1 ELSE 0 END) AS CourseworkMarkOver50To59,
SUM(CASE WHEN CourseworkMark BETWEEN 40 and 49 THEN 1 ELSE 0 END) AS CourseworkMarkOver40To49,
SUM(CASE WHEN CourseworkMark < 40 THEN 1 ELSE 0 END) AS CourseworkMarkUnder40
FROM tblModules INNER JOIN tblEnrolments
ON tblModules.GroupNo = tblEnrolments.GroupNo
GROUP BY Title;
Related
My project is a clothes factory and I have 3 tables.
Person : A table that contains people's name
Category : Contains each category of clothes in the factory (sockets, shoes, etc.)
Quantity : The quantity of clothes for each person
SELECT Name,
sum(case when category = 'shoes' then quantity else 0 end) as 'Quantity_shoes',
sum(case when category = 'shirts' then quantity else 0 end) as 'Quantity_shirts',
sum(case when category = 'sockets' then quantity else 0 end) as 'Quantity_shirts',
sum(case when category = 'hats' then quantity else 0 end) as 'Quantity_hats'
FROM person p
join inventory i
on i.person_id = p.id
join category c
c.id = i.category_id
WHERE p = 'Paul'
GROUP BY name,
category
And I'm trying to display something like this :
Name
Quantity_shoes
Quantity_shirts
Quantity_sockets
Quantity_hats
Paul
8
25
38
0
But my result isn't that I expected... I got this :
Name
Quantity_shoes
Quantity_shirts
Quantity_sockets
Quantity_hats
Paul
8
0
0
0
Paul
0
0
0
0
Paul
0
25
0
0
Paul
0
0
38
0
It seems that I have one row for each category. So I tried to groupbyquantity but it doesn't sum my quantity and I have more rows.
What I am doing wrong?
As suggested in the above try this (I am guessing the column in person with the name is p.name in which case you may not even need the group by name):
SELECT
Name,
sum(case when category = 'shoes' then quantity else 0 end) as 'Quantity_shoes',
sum(case when category = 'shirts' then quantity else 0 end) as 'Quantity_shirts',
sum(case when category = 'sockets' then quantity else 0 end) as 'Quantity_shirts',
sum(case when category = 'hats' then quantity else 0 end) as 'Quantity_hats'
FROM
person p
join inventory i on i.person_id = p.id
join category c.id = i.category_id
WHERE
p.name = 'Paul'
I have A attendance report in which I want to show report day wise like this :
I can calculate Sum individually , But not the total of all Sum
My StudentAttendance Table :
ID ClassID SubjectID Day10 Day11 Day12 Day13 Day14 Day15 ProfessorID
215 23 46 P 36 36
216 23 47 P 36
217 23 48 P 36 P 36
218 17 35 P 28
I have Tried this Query :
select ClassID,
sum(case when Day14= 'P' then 1 else 0 end) Present,
sum(case when Day14= 'A' then 1 else 0 end) Absent,
sum(case when Day14= 'L' then 1 else 0 end) Leave
from studentattendance
group by ClassID,Day14
I tried Sum(Present.Absent,Leave)..But not working What I am missing ??
There is no SQL syntax for a SELECT with multiple FROM clauses(WITHOUT nesting).
Perhaps you want something like this?
select
classID,
count(Day14) Total,
sum(case when Day14='P' then 1 else 0 end) Present,
sum(case when Day14='A' then 1 else 0 end) Absent,
sum(case when Day14='L' then 1 else 0 end) Leave
from studentattendance
group by classID
Here Total is merely the total number of records in each classID. The sum(case..when..) statements simulates a selective count() only when certain condition is satisfied (Day14 is either Present,Absent or Leave). Note that there is no guarantee that the Total to be equal to Present+Absent+Leave if you expect values other than these 3 to be present in the column Day14
I want to know what percentage of records have a given value, where percentage is defined as the number of records that match the value divided by the total number of records. i.e. if there are 100 records, of which 10 have a null value for student_id and 20 have a value of 999999, then the percentage_999999 should be 20%. Can I use the AVG function to determine this?
Option 1:
SELECT year, college_name,
sum(case when student_id IN ('999999999') then 1 else 0 end) as count_id_999999999,
count_id_999999999/total_id as percent_id_999999999,
sum(case when student_id IS NULL then 1 else 0 end) as count_id_NULL,
count_id_NULL/total_id as percent_id_NULL
count(*) as total_id
FROM enrolment_data ed
GROUP BY year, college_name
ORDER BY year, college_name;
Option 2:
SELECT year, college_name,
sum(case when student_id IN ('999999999') then 1 else 0 end) as count_id_999999999,
avg(case when student_id IN ('999999999') then 1.0 else 0 end) as percent_id_999999999,
sum(case when student_id IS NULL then 1 else 0 end) as count_id_NULL,
avg(case when student_id IS NULL then 1.0 else 0 end) as percent_id_NULL
count(*) as total_id
FROM enrolment_data ed
GROUP BY year, college_name
ORDER BY year, college_name;
I created a similar table with 100 records, 20 999999999s, 10 nulls, and 70 1s. This worked for me on SQL Server:
select count(*), StudentID
from ScratchTbl
group by StudentID;
(No column name) StudentID
10 NULL
70 1
20 999999999
select avg(case when StudentID = '999999999' then 1.0 else 0.0 end) as 'pct_9s',
sum(case when StudentID = '999999999' then 1 else 0 end) as 'count_9s',
avg(case when StudentID is null then 1.0 else 0.0 end) as 'pct_null',
sum(case when StudentID is null then 1 else 0 end) as 'count_null'
from ScratchTbl
pct_9s count_9s pct_null count_null
0.200000 20 0.100000 10
I have a feeling that your use of the group by clause could be creating problems for you, perhaps select a specific year/college using the where clause (and get rid of the group by line) and see if you get the results you expect.
I have a huge database with over 4 million rows that look like that:
Customer ID Shop
1 Asda
1 Sainsbury
1 Tesco
2 TEsco
2 Tesco
I need to count customers that within last 4 weeks had shopped in all 3 shops Tesco Sainsbury and Asda. Can you please advice if its possible to do it with subqueries?
This is an example of a "set-within-sets" subquery. You can solve it with aggregation:
select customer_id
from Yourtable t
where <shopping date within last four weeks>
group by customer_id
having sum(case when shop = 'Asda' then 1 else 0 end) > 0 and
sum(case when shop = 'Sainsbury' then 1 else 0 end) > 0 and
sum(case when shop = 'Tesco' then 1 else 0 end) > 0;
This structure is quite flexible. So if you wanted Asda and Tesco but not Sainsbury, then you would do:
select customer_id
from Yourtable t
where <shopping date within last four weeks>
group by customer_id
having sum(case when shop = 'Asda' then 1 else 0 end) > 0 and
sum(case when shop = 'Sainsbury' then 1 else 0 end) = 0 and
sum(case when shop = 'Tesco' then 1 else 0 end) > 0;
EDIT:
If you want a count, then use this as a subquery and count the results:
select count(*)
from (select customer_id
from Yourtable t
where <shopping date within last four weeks>
group by customer_id
having sum(case when shop = 'Asda' then 1 else 0 end) > 0 and
sum(case when shop = 'Sainsbury' then 1 else 0 end) > 0 and
sum(case when shop = 'Tesco' then 1 else 0 end) > 0
) t
the output i would like to display was accumulator of total EMPL_NUM. For example, the value show in the field TOTAL_FEBRUARY=TOTAL_JANUARY+TOTAL_FEBRUARY,while for the value exist in field TOTAL_MARCH=TOTAL_MARCH+TOTAL_JANUARY+TOTAL_FEBRUARY. I hope some of you can provide the solution for do it. Thank you very much. The coding is show as below:
SELECT
(CASE WHEN To_Char(A.EFFDT,'MM')=01 THEN 1
WHEN To_Char(A.EFFDT,'MM')=02 THEN 2
WHEN To_Char(A.EFFDT,'MM')=03 THEN 3
WHEN To_Char(A.EFFDT,'MM')=04 THEN 4
WHEN To_Char(A.EFFDT,'MM')=05 THEN 5
WHEN To_Char(A.EFFDT,'MM')=06 THEN 6
WHEN To_Char(A.EFFDT,'MM')=07 THEN 7
WHEN To_Char(A.EFFDT,'MM')=08 THEN 8
WHEN To_Char(A.EFFDT,'MM')=09 THEN 9
WHEN To_Char(A.EFFDT,'MM')=10 THEN 10
WHEN To_Char(A.EFFDT,'MM')=11 THEN 11
WHEN To_Char(A.EFFDT,'MM')=12 THEN 12
ELSE NULL END) AS MONTHS
,Count(*) AS EMPL_NUM
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=01 THEN 1 ELSE 0 END) AS TOTAL_JANUARY
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=02 THEN 1 ELSE 0 END) AS TOTAL_FEBRUARY
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=03 THEN 1 ELSE 0 END) AS TOTAL_MARCH
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=04 THEN 1 ELSE 0 END) AS TOTAL_APRIL
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=05 THEN 1 ELSE 0 END) AS TOTAL_MAY
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=06 THEN 1 ELSE 0 END) AS TOTAL_JUN
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=07 THEN 1 ELSE 0 END) AS TOTAL_JULY
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=08 THEN 1 ELSE 0 END) AS TOTAL_AUGUST
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=09 THEN 1 ELSE 0 END) AS TOTAL_SEPTEMBER
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=10 THEN 1 ELSE 0 END) AS TOTAL_OCTOBER
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=11 THEN 1 ELSE 0 END) AS TOTAL_NOVEMBER
,Sum(CASE WHEN To_Char(A.EFFDT,'MM')=12 THEN 1 ELSE 0 END) AS TOTAL_DECEMBER
FROM PS_JOB A
,PS_CITIZEN_PSSPRT B
,PS_CITIZENSHIP C
,PS_CITIZEN_STS_TBL D
WHERE A.HR_STATUS='A'
AND A.EFFDT=(SELECT Max(A1.EFFDT) FROM PS_JOB A1 WHERE A.EMPLID=A1.EMPLID AND A.EMPL_RCD=A1.EMPL_RCD AND A1.EFFDT<=SYSDATE)
AND A.EMPL_RCD=0
AND A.EFFSEQ=(SELECT Max(A2.EFFSEQ) FROM PS_JOB A2 WHERE A.EMPLID=A2.EMPLID AND A.EMPL_RCD=A2.EMPL_RCD AND A.EFFDT=A2.EFFDT)
AND A.EMPLID =B.EMPLID(+)
AND B.DEPENDENT_ID=' '
AND A.EMPLID=C.EMPLID
AND B.EMPLID=C.EMPLID
AND B.DEPENDENT_ID=C.DEPENDENT_ID
AND B.COUNTRY=C.COUNTRY
AND B.COUNTRY=D.COUNTRY
AND C.COUNTRY=D.COUNTRY
AND C.CITIZENSHIP_STATUS=D.CITIZENSHIP_STATUS
AND C.CITIZENSHIP_STATUS IN ('5','7')
AND To_Char(A.EFFDT,'YYYY')=2012
GROUP BY CASE WHEN To_Char(A.EFFDT,'MM')=01 THEN 1
WHEN To_Char(A.EFFDT,'MM')=02 THEN 2
WHEN To_Char(A.EFFDT,'MM')=03 THEN 3
WHEN To_Char(A.EFFDT,'MM')=04 THEN 4
WHEN To_Char(A.EFFDT,'MM')=05 THEN 5
WHEN To_Char(A.EFFDT,'MM')=06 THEN 6
WHEN To_Char(A.EFFDT,'MM')=07 THEN 7
WHEN To_Char(A.EFFDT,'MM')=08 THEN 8
WHEN To_Char(A.EFFDT,'MM')=09 THEN 9
WHEN To_Char(A.EFFDT,'MM')=10 THEN 10
WHEN To_Char(A.EFFDT,'MM')=11 THEN 11
WHEN To_Char(A.EFFDT,'MM')=12 THEN 12
ELSE NULL END
nter code here
Use <= operator when calculating SUM, e.g.:
Sum(CASE WHEN TO_NUMBER(To_Char(A.EFFDT,'MM')) <= 3 THEN 1 ELSE 0 END) AS TOTAL_MARCH
I think what you are asking for is a running total. Take a look at analytic functions (for example, the psoug site). If the core of your query is correct, do a regular aggregate in the inner query, then wrap that in an analytic function for the running total.
SELECT month
,SUM(month_count) OVER ( ROWS BETWEEN UNBOUNDED PRECEDING
AND CURRENT ROW )
AS running_total
FROM ( SELECT To_Char(A.EFFDT,'MM') AS month
,COUNT(*) AS month_count
FROM PS_JOB A
,PS_CITIZEN_PSSPRT B
,PS_CITIZENSHIP C
,PS_CITIZEN_STS_TBL D
WHERE A.HR_STATUS='A'
AND A.EFFDT=( SELECT Max(A1.EFFDT)
FROM PS_JOB A1
WHERE A.EMPLID=A1.EMPLID
AND A.EMPL_RCD=A1.EMPL_RCD
AND A1.EFFDT<=SYSDATE )
AND A.EMPL_RCD=0
AND A.EFFSEQ=( SELECT Max(A2.EFFSEQ)
FROM PS_JOB A2
WHERE A.EMPLID=A2.EMPLID
AND A.EMPL_RCD=A2.EMPL_RCD
AND A.EFFDT=A2.EFFDT )
AND A.EMPLID =B.EMPLID(+)
AND B.DEPENDENT_ID=' '
AND A.EMPLID=C.EMPLID
AND B.EMPLID=C.EMPLID
AND B.DEPENDENT_ID=C.DEPENDENT_ID
AND B.COUNTRY=C.COUNTRY
AND B.COUNTRY=D.COUNTRY
AND C.COUNTRY=D.COUNTRY
AND C.CITIZENSHIP_STATUS=D.CITIZENSHIP_STATUS
AND C.CITIZENSHIP_STATUS IN ('5','7')
AND To_Char(A.EFFDT,'YYYY')=2012
GROUP BY To_Char(A.EFFDT,'MM')
)
ORDER BY month