I need to display the Youngest Athlete in my database. MIN(Athlete.Age) works fine, but I need the name as well obviously. When I add the Name to select I get about 5 results. How do I display just the MIN(Age) and her name?
select MIN(Athlete.Age), Athlete.Name
from (((Country INNER JOIN Athlete ON Country.Country_Code = Athlete.Country_Code)
INNER JOIN Athlete_event
ON Athlete.Athlete_ID = Athlete_event.Athlete_ID2)
INNER JOIN Event
ON Event.Event_ID = Athlete_event.Event_ID2)
Where Athlete.Athlete_ID = Event.Award_Gold
GROUP BY Athlete.Name;
You may have 5 athletes with the same age. The query will not know which one you want.
If you have the birth-dates in the database, try using that.
[edit] Storing age is generally not a good idea because in one year, they will all be wrong.
[edit2] Note it is still possible for people to share the same birthday.
select *
from
(
select Athlete.Age, Athlete.Name
from (((Country INNER JOIN Athlete ON Country.Country_Code = Athlete.Country_Code)
INNER JOIN Athlete_event
ON Athlete.Athlete_ID = Athlete_event.Athlete_ID2)
INNER JOIN Event
ON Event.Event_ID = Athlete_event.Event_ID2)
Where Athlete.Athlete_ID = Event.Award_Gold
order by Age
) v
where rownum=1;
add this line on your query
HAVING MIN(Athlete.Age) = (SELECT MIN(AGE) from Athlete)
so your final query will look like
SELECT MIN(Athlete.Age),
Athlete.NAME
FROM (((Country INNER JOIN Athlete
ON Country.Country_Code = Athlete.Country_Code
) INNER JOIN Athlete_event
ON Athlete.Athlete_ID = Athlete_event.Athlete_ID2
) INNER JOIN Event
ON Event.Event_ID = Athlete_event.Event_ID2
)
WHERE Athlete.Athlete_ID = Event.Award_Gold
GROUP BY Athlete.NAME
HAVING MIN(Athlete.Age) = ( SELECT MIN(AGE) FROM Athlete )
if you use the GROUP BY in your query, you are searching the min age of each athlete.
You should try with a subquery. Adding it to your where clause. Something like: (Not tested)
select Athlete.Age, Athlete.Name
from Athlete
AND Athlete.Age = (select MIN(Athlete.Age)
from (((Country INNER JOIN Athlete ON Country.Country_Code = Athlete.Country_Code)
INNER JOIN Athlete_event
ON Athlete.Athlete_ID = Athlete_event.Athlete_ID2)
INNER JOIN Event
ON Event.Event_ID = Athlete_event.Event_ID2)
Where Athlete.Athlete_ID = Event.Award_Gold);
Related
I am working with sql server through SSMS right now. How can i choose all people with multiple(>2)vacancies?
I am trying something like that, but i dont understand how to make part with "more than 2 vacancies"?
SELECT dbo.applicants.FirstName, dbo.vacancy.Name
FROM dbo.applicants INNER JOIN
dbo.VacancyApplicant ON dbo.applicants.id = dbo.VacancyApplicant.ApplicantId INNER JOIN
dbo.vacancy ON dbo.VacancyApplicant.VacancyId = dbo.vacancy.id WHERE dbo.vacancy.Name='third vacancy'
SELECT dbo.applicants.FirstName, dbo.vacancy.Name
FROM dbo.applicants A INNER JOIN
dbo.VacancyApplicant V ON A.id = V.ApplicantId
WHERE EXIST(
SELECT 1
FROM dbo.applicants INNER JOIN
dbo.VacancyApplicant ON dbo.applicants.id =
dbo.VacancyApplicant.ApplicantId INNER JOIN
dbo.vacancy ON dbo.VacancyApplicant.VacancyId = dbo.vacancy.id
WHERE A.id=dbo.applicants.id
GROUP BY dbo.applicants.id,dbo.vacancy.id
HAVING COUNT(1)>2
)
Group By and Having are you basic answer. Below is a simple solution, might not be ideal, but can give you the idea.
I am finding target "applicants" ids in subquery, that uses GROUP BY and HAVING then outer query joins to that to output FirstName and LastName of applicant
SELECT dbo.applicants.FirstName, dbo.applicants.LastName FROM
dbo.applicants a INNER JOIN
(
SELECT dbo.applicants.id
FROM dbo.applicants INNER JOIN
dbo.VacancyApplicant ON dbo.applicants.id = dbo.VacancyApplicant.ApplicantId INNER JOIN
dbo.vacancy ON dbo.VacancyApplicant.VacancyId = dbo.vacancy.id AND dbo.vacancy.Name='third vacancy'
GROUP BY dbo.applications.id
HAVING COUNT(dbo.vacancy.id) > 2
) targetIds ON a.id = targetIds.id
"more than 2 vacancies"?
Your question only mentions vacancies but your query is filtering for a particular name. I assume you really want more than two of that name.
If I understand correctly, you want aggregation:
SELECT a.FirstName, a.Name
FROM dbo.applicants a INNER JOIN
dbo.VacancyApplicant va
ON a.id = va.ApplicantId INNER JOIN
dbo.vacancy v
ON va.VacancyId = v.id
WHERE v.Name = 'third vacancy'
GROUP BY a.FirstName, v.Name
HAVING COUNT(*) > 2;
Note the use of table aliases. They make the query easier to write and to read.
WITH TempCTE AS (
SELECT DISTINCT ap.FirstName
,vc.Name
,COUNT (va.VacancyId) OVER (PARTITION BY ap.id) AS NoOfVacancies
FROM dbo.applicants ap
JOIN dbo.VacancyApplicant va
ON ap.id = va.ApplicantId
JOIN dbo.vacancy vc
ON va.VacancyId = vc.id
)
SELECT FirstName,[Name], NoOfVacancies FROM TempCTE
WHERE NoOfVacancies > 2
I am trying to create one single query that will give me a distinct count for both the ActivityID and the CommentID. My query in MS Access looks like this:
SELECT
tbl_Category.Category, Count(tbl_Activity.ActivityID) AS CountOfActivityID,
Count(tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;
I know the answer must somehow include SELECT DISTINCT but am not able to get it to work. Do I need to create multiple subqueries?
This is really painful in MS Access. I think the following does what you want to do:
SELECT ac.Category, ac.num_activities, aco.num_comments
FROM (SELECT ca.category, COUNT(*) as num_activities
FROM (SELECT DISTINCT c.Category, a.ActivityID
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as caa
GROUP BY ca.category
) as ca LEFT JOIN
(SELECT c.Category, COUNT(*) as num_comments
FROM (SELECT DISTINCT c.Category, co.CommentId
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as aco
GROUP BY c.Category
) as aco
ON aco.CommentId = ac.CommentId
Note that your LEFT JOINs are superfluous because the WHERE clause turns them into INNER JOINs. This adjusts the logic for that purpose. The filtering is also very tricky, because it uses both tables, requiring that both subqueries have both JOINs.
You can use DISTINCT:
SELECT
tbl_Category.Category, Count(DISTINCT tbl_Activity.ActivityID) AS CountOfActivityID,
Count(DISTINCT tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;
I need help regarding query optimization of the below query.
SELECT pr.todate , pr.descr, cmp.company_id
FROM employee AS emp
INNER JOIN company AS cmp ON emp.emp_comp_id = cmp.company_id
INNER JOIN profile AS pr ON emp.acca_id = pr.profile_id
INNER JOIN acondition ON as_id = as_ac_id
WHERE as_closed = 0
AND (pr.ac_act_id = 20)
AND (pr.todate = (SELECT MIN(todate) AS Expr1
FROM profile pro
INNER JOIN employee empl ON empl.acca_id = pro.profile_id
JOIN acondition ON as_id = as_ac_id
WHERE (pro.ac_act_id = 20
AND empl.emp_comp_id = cmp.company_id)
AND as_closed = 0))
Since there are duplicate joins in the main query and sub query, is there any way to remove those joins in the subquery?
Since, as you clarified, your sub-query is almost identical to your main query you might be able to use the window function RANK as a filter condition. RANK assigns the same number to ties, meaning if multiple records per company match you will get them all e.g.
SELECT todate, descr, company_id
FROM (
SELECT pr.todate, pr.descr, cmp.company_id
, RANK() OVER (PARTITION BY cmp.company_id ORDER BY pr.todate ASC) RankNumber
FROM employee AS emp
INNER JOIN company AS cmp ON emp.emp_comp_id = cmp.company_id
INNER JOIN profile AS pr ON emp.acca_id = pr.profile_id
INNER JOIN acondition ON as_id = as_ac_id
WHERE as_closed = 0 AND pr.ac_act_id = 20
) X
where RankNumber = 1;
Does this work for you?
SELECT ca.todate , pr.descr, cmp.company_id
FROM employee AS emp
INNER JOIN company AS cmp ON emp.emp_comp_id = cmp.company_id
CROSS APPLY (
SELECT TOP(1) pr.todate
FROM profile pr
INNER JOIN acondition ON as_id = as_ac_id
WHERE emp.acca_id = pr.profile_id AND (pr.ac_act_id = 20) AND as_closed = 0
ORDER BY pr.todate ASC
) AS ca
I am trying to get a list of our users from our database along with the number of people from the same cohort as them - which in this case is defined as being from the same medical school at the same time.
medical_school_id is stored in the doctor_record table
graduation_dt is stored in the doctor_record table as well.
I have managed to write this query out using a subquery which does a select statement counting the number of others for each row but this takes forever. My logic is telling me that I ought to run a simple GROUP BY query once first and then somehow JOIN the medical_school_id on to that.
The group by query is as follows
select count(ca.id) , cdr.medical_school_id, cdr.graduation_dt
from account ca
LEFT JOIN doctor cd on ca.id = cd.account_id
LEFT JOIN doctor_record cdr on cd.gmc_number = cdr.gmc_number
GROUP BY cdr.medical_school_id, cdr.graduation_dt
The long select query is
select a.id, a.email , dr.medical_school_id,
(select count(ba.id) from account ba
LEFT JOIN doctor bd on ba.id = bd.account_id
LEFT JOIN doctor_record bdr on bd.gmc_number = bdr.gmc_number
WHERE bdr.medical_school_id = dr.medical_school_id AND bdr.graduation_dt = dr.graduation_dt) AS med_count,
from account a
LEFT JOIN doctor d on a.id = d.account_id
LEFT JOIN doctor_record dr on d.gmc_number = dr.gmc_number
If you could push me in the right direction that would be amazing
I think you just want window functions:
select a.id, a.email, dr.medical_school_id, dr.graduation_dt,
count(*) over (partition by dr.medical_school_id, dr.graduation_dt) as cohort_size
from account a left join
doctor d
on a.id = d.account_id left join
doctor_record dr
on d.gmc_number = dr.gmc_number;
Using your same code for group by:
SELECT * FROM (
(
SELECT acc.[id]
, acc.[email]
FROM
account acc
LEFT JOIN
doctor doc
ON
acc.id = doc.account_id
LEFT JOIN
doctor_record doc_rec
ON
doc.gmc_number = doc_rec.gmc_number
) label
LEFT JOIN
(
SELECT count(acco.id)
, doc_reco.medical_school_id
, doc_reco.graduation_dt
FROM
account acco
LEFT JOIN
doctor doct
ON
acco.id = doct.account_id
LEFT JOIN
doctor_record doc_reco
ON
doct.gmc_number = doc_reco.gmc_number
GROUP BY
doc_reco.medical_school_id,
doc_reco.graduation_dt
) count
ON
count.[medical_school_id]=label.[medical_school_id]
AND
count.[graduation_dt]=label.[graduation_date]
)
how about something like this?
select a.doctor_id
, count(*) - 1
from doctor_record a
left join doctor_record b on a.medical_school_id = b.medical_school_id
and a.graduation_dt = b.graduation_dt
group by a.doctor_id
Subtract 1 from the count so that you're not counting the doctor in the "other folks in same cohort" number
I'm defining "same cohort" as "same medical school & graduation date".
I'm unclear on what GMC number is and how it is related. Is it something to do with cohort?
I have a query like this:
SELECT m...., a...., r....
FROM 0_member AS m
LEFT JOIN 0_area AS a ON a.user_id = (SELECT user_id
FROM `0_area`
WHERE user_id = m.id
ORDER BY sec_id ASC LIMIT 1)
LEFT JOIN 0_rank as r ON a.rank_id = r.id
WHERE m.login_userid = '$username'
The idea is to get the first row from 0_area table and hence the attempted inner join. However, it is not working as expected.
Between 0_area and 0_member, 0_member.id = 0_area.user_id. However, there are multiple rows of 0_area.user_id and I want the row having the lowest value of sec_id.
Any help please?
SELECT m...., a...., r....
FROM 0_member AS m
LEFT JOIN (SELECT user_id, min(sec_id) minsec
FROM `0_area`
GROUP BY user_id) g1 on g1.user_id=m.id
LEFT JOIN 0_area AS a ON a.user_id = g1.user_id and a.sec_id=minsec
LEFT JOIN 0_rank as r ON a.rank_id = r.id
WHERE m.login_userid = '$username'