I have a table with columns:
COURSE_ID (int)
SKILL_ID (int)
One course could have many skills, for example the table could contain values:
COURSE_ID
SKILL_ID
1
1
1
2
2
2
2
3
2
4
3
1
4
1
4
2
The result should show count of courses and count of skills they have.
For example for the table above the result should be:
1 = 1 (course 3 has 1 skill) (count course with 1 skill = 1)
2 = 2 (course 1 and 4 have 2 skills) (count course with 2 skill = 2)
3 = 1 (course 2 has 3 skills) (count course with 3 skill = 1)
Could anybody help with this query?
And one more question. I tried to execute this query and I am expecting one number with count of courses with 6 skills, but I got many records (in fact - rows count = expected result, value in rows = 6), can't understand why, could anybody explain?
select count(table.course_id) from Table table
GROUP BY table.course_id
HAVING COUNT(table.skill_id) = 6
It's not entirely clear what you're expecting as a result but I think this is what you're after
select Skill, Count(*) courseCount
from (
select course_id, Count(distinct SKILL_ID) Skill
from t
group by COURSE_ID
)s
group by Skill;
DB<>Fiddle
Result:
Try
select table.course_id, count(table.skill_id)
from table_name table
GROUP BY table.course_id
And your query should be
select table.course_id, count(table.skill_id)
from table_name table
GROUP BY table.course_id
HAVING COUNT(table.skill_id) = 6
Related
I have a form which have stars for rating from 1-5
i have count each user hits over individual value
Now i need to have count() of my table along with my result
i have achieved this with sub-query but for me cost of query matters that's why i am tired
to calculate count() along with my existing query.
How to add a column with existing record which calculate count of all records in table.?
I will attach my output
WITH survey AS (
SELECT
*
FROM
(
SELECT
student_id,
performance,
teacher_behaviour,
syllabus,
survey_id
FROM
survey_feedback
WHERE
survey_id = 1
GROUP BY
student_id,
performance,
teacher_behaviour,
syllabus,
survey_id
) UNPIVOT ( star
FOR q
IN ( performance AS 'PERFORMANCE',
teacher_behaviour AS 'TEACHER_BEHAVIOUR',
syllabus AS 'SYLLABUS' ) )
ORDER BY
1,
2
)
SELECT
*
FROM
survey PIVOT (
COUNT ( student_id )
FOR star
IN ( 1, 2, 3, 4, 5 )
)
ORDER BY
q;
Output is
1 PERFORMANCE 0 1 2 2 1
1 SYLLABUS 2 2 2 0 0
1 TEACHER_BEHAVIOUR 2 0 1 1 2
Desired Output is
1 PERFORMANCE 0 1 2 2 1 6 <-Want this total count of table
1 SYLLABUS 2 2 2 0 0 6
1 TEACHER_BEHAVIOUR 2 0 1 1 2 6
I am trying to do a count from multiple tables but there could be multiple entries in each table. Here is simple sample data simplified. There are actually more then 3 tables but just so I get an understanding of how to do it
table2 table2 table3
person_ID person_id person_id
1 1 2
2 1 2
3 2 1
4 2 4
5 4 5
I'm trying to get a count of each person ID in each table so the output would be the following. Note that personID is a key I don't need the addition of the number of the ID not 2+2+2+2. But the count of the number of appearances it makes in the all tables then the count in each table added together for total number of appearances it makes. Basically I'm trying to find a total number of items attached to each personID
person_id total
1 4
2 4
3 1
4 3
5 2
Select the ids from all the tables together withunion. That result can be grouped by the id and counted for each
select person_id, count(*) as count
from
(
select person_id from table1
union all
select person_id from table2
union all
select person_id from table3
) tmp
group by person_id
It's my first question here so I hope I can explain it well enough,
I want to order my data by amount of occurrences in the table.
My table is like this:
id Daynr
1 2
1 4
2 4
2 5
2 6
3 1
4 2
4 5
And I want it to sort it like this:
id Daynr
3 1
1 2
1 4
4 2
4 5
2 4
2 5
2 6
Player #3 has one day in the table, and Player #1 has 2.
My table is named "dayid"
Both id and Daynr are foreign keys, together making it a primary key
I hope this explains my problem enough, Please ask for more information it's my first time here.
Thanks in advance
You can do this by counting the number of times that things occur for each id. Most databases support window functions, so you can do this as:
select id, daynr
from (select t.*, count(*) over (partition by id) as cnt
from table t
) t
order by cnt, id;
You can also express this as a join:
select t.id, t.daynr
from table as t inner join
(select id, count(*) as cnt
from table
group by id
) as tg
on t.id = tg.id
order by tg.cnt, id;
Note that both of these include the id in the order by. That way, if two ids have the same count, all rows for the id will appear together.
I have a data set with four columns (author, document, rating 1, rating 2)
How do I pick authors who have written a document that has been rated higher in rating 1 than rating 2, and has also written another document that has been rated higher in rating 2 than rating 1.
Basically:
AUTHOR DOCUMENT RATING 1 RATING 2
A 1 1 2
B 2 1 2
B 3 3 1
C 4 2 2
C 5 3 4
C 6 1 3
D 7 1 2
D 8 1 2
So my desired query will give me B and C because it has written docs that have had both higher and lower numbers in both ratings.
What I have:
SELECT DISTINCT author
FROM(
(SELECT author
FROM table_name
WHERE rating1 < rating2)
UNION
(SELECT author
FROM table_name
WHERE rating1 > rating2)
)
AS a
What I cant figure out is how to group the authors, test whether rating 1 and rating 2 are both higher and lower, output the name and then move on to the next group of authors. What the above prints is just the set of distinct names with either higher or lower numbers. So this one would print D as well for example.
What is my SQL code missing that would satisfy the criteria mentioned above
Try this,
select *
from myTable as t1
inner join MyTable as t2
on t1.author = t2.author
and t2.rating1 > t2.rating2
where t1.rating1 > t1.rating2
Essentially what I'm trying to do is count the number of rows something doesn't exist in an audit/history table. I'd like the following query to return a count of one per detail. Currently it gives me one per row in the history table.
--Detail Table
ID DETAIL_GROUP
1 A
2 B
3 B
--Detail History Table
DETAIL_ID_FK VALUE1
1 NOT_MATCH
1 NOT_MATCH
2 MATCH
2 NOT_MATCH
3 MATCH
3 NOT_MATCH
SELECT D.DETAIL_GROUP, COUNT(*)
FROM DETAIL D
WHERE (NOT EXISTS(
SELECT NULL
FROM DETAIL_HISTORY HI
WHERE HI.D_ID_FK = D.ID
AND HI.VALUE1 = 'MATCH'))
GROUP BY D.DETAIL_GROUP;
I'd like to see the following result:
DETAIL_GROUP COUNT(*)
A 1
but I'm receiving the following result:
DETAIL_GROUP COUNT(*)
A 2
Thank you in advance for any assistance provided.
Assuming that your detail table is as follows:
D_ID VALUE1
1 MATCH
1 NOT_MATCH
2 MATCH
2 NOT_MATCH
3 MATCH
3 NOT_MATCH
The below query:
SELECT d.detail_group, count(*)
FROM detail d
JOIN detail_history dh ON dh.d_id = d.id
WHERE dh.value1 = 'MATCH'
GROUP BY d.detail_group
Would produce:
DETAIL_GROUP COUNT(*)
A 1
B 2
The above query creates the groups matching the ids and then goes into each group and restricts the items based on value1.