So, i need help doing a select inside a subquery, i know this is kinda basics but i can't manage to do it by myself yet.
(Reparacao=repairs and lojas=stores, from portuguese to english)
I want to get the number of repairs that each store has. However i can only do one store at a time, but i want a query that selects all the stores.
I'm using this query:
SELECT COUNT( DISTINCT id_reparacao ) , lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = 1
WHERE id_loja = lojas.id
and i want something like:
SELECT COUNT( DISTINCT id_reparacao ) , lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = (Select id from lojas) //i want the id of every store
WHERE id_loja = lojas.id
Try this:
There is no need to use sub query to fetch all repairs count by stores.
You can easily get the result using JOIN and GROUP BY.
SELECT COUNT(DISTINCT id_reparacao) repairCnt, lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = id_loja
GROUP BY lojas.id
Why don't you try to join ON ids:
SELECT COUNT( DISTINCT r.id_reparacao ) , lojas.nome
FROM reparacoes r
INNER JOIN lojas l ON l.id = r.id_loja;
Related
Following query shows the results I need from table pointsList (latest records per user grouped by column idMatch)
select * from pointsList p
inner join ( select idMatch, max(datePointsCalculated ) as MaxDate from pointsList group by idMatch ) tm
on p.idMatch = tm.idMatch and p.datePointsCalculated = tm.MaxDate
order by p.idMatch ASC
But now I want to also select some additional information about the user (from table users). My naive way to tackle this was by making a new inner join like this:
select * from pointsList p, users u
inner join users
on u.idUser = p.idUser
inner join ( select idMatch, max(datePointsCalculated ) as MaxDate from pointsList group by idMatch ) tm
on p.idMatch = tm.idMatch and p.datePointsCalculated = tm.MaxDate
order by p.idMatch ASC
But I get the error message "unknown column 'p.idUser' in on clause". I tried using users.idUser and pointsList.idUser and other combinations (renaming pointsList in the on-clouse) but I always get the unknown column error (pointsList.idUser really does exist). Anyone could explain what I am doing wrong? I would like to extend this query to another table as well.
Thank you in advance!
Comma , priority in FROM clause is less than JOIN priority. And your query acts as:
select * from pointsList p,
(
users u
inner join users
on u.idUser = p.idUser
inner join ( select idMatch, max(datePointsCalculated ) as MaxDate from pointsList group by idMatch ) tm
on p.idMatch = tm.idMatch and p.datePointsCalculated = tm.MaxDate
)
order by p.idMatch ASC
Of course, table pointsList AS p is not accessible within the parenthesis.
Use CROSS JOIN instead of comma:
select * from pointsList p
CROSS JOIN users u
inner join users
on u.idUser = p.idUser
inner join ( select idMatch, max(datePointsCalculated ) as MaxDate from pointsList group by idMatch ) tm
on p.idMatch = tm.idMatch and p.datePointsCalculated = tm.MaxDate
order by p.idMatch ASC
I am trying to make a query to fetch the newest car for each user:
select * from users
left join
(select cars.* from cars
where cars.userid=users.userid
order by cars.year desc limit 1) as cars
on cars.userid=users.userid
It looks like it says Unknown column "users.userid" in where clause
I tried to remove cars.userid=users.userid part, but then it only fetches 1 newest car, and sticks it on to each user.
Is there any way to accomplish what I'm after? thanks!!
For this purpose, I usually use row_number():
select *
from users u left join
(select c.* , row_number() over (partition by c.userid order by c.year desc) as seqnum
from cars c
) c
on c.userid = u.userid and c.seqnum = 1;
One option is to filter the left join with a subquery:
select * -- better enumerate the columns here
from users u
left join cars c
on c.userid = u.userid
and c.year = (select max(c1.year) from cars c1 where c1.userid = c.userid)
For performance, consider an index on car(userid, year).
Note that this might return multiple cars per user if you have duplicate (userid, year) in cars. It would be better to have a real date rather than just the year.
Maybe there are better and more efficient way to query this. Here is my solution;
select users.userid, cars.*
from users
left join cars on cars.userid = users.userid
join (SELECT userid, MAX(year) AS maxDate
FROM cars
GROUP BY userid) as sub on cars.year = sub.maxDate;
I have a query
SELECT s.*
, g.*
from tbl_section1 as s
, tbl_game as g
LEFT
JOIN tbl_game_visit_count AS gvc
ON g.game_id = gvc.game_id
where s.category_id = g.game_id
ORDER
BY g.udate DESC
, gvc.visit_count DESC
which works fine.
But I want to fetch the first record ordered by g.udate, and then the rest of the records ordered by gvc.visit_count.
Is this possible using mysql query?
Thanks in advance.
It could be possible by using UNION(not UNION ALL, since we don't want to duplicate rows ) between two queries with ORDER BY and LIMIT clauses inside parentheses
SELECT q.*
FROM
(
SELECT s.*, g.*
FROM tbl_section1 as s
INNER JOIN tbl_game as g ON s.category_id = g.game_id
LEFT JOIN tbl_game_visit_count AS gvc ON g.game_id = gvc.game_id
ORDER BY g.udate DESC
LIMIT 1
) q
UNION
SELECT s.*, g.*
FROM tbl_section1 as s
INNER JOIN tbl_game as g ON s.category_id = g.game_id
LEFT JOIN tbl_game_visit_count AS gvc ON g.game_id = gvc.game_id
ORDER BY gvc.visit_count DESC;
P.S. Because of your original query I kept DESC options for ORDER BY, you can get rid of them if you want regular ascending ordering.
Below is my query to display district, but I need to select all data whose district = nagpur
My means in, I want to put where condition in my query. Please suggest me how to implement where condition in below query.
SELECT RES.PARTYNAME, RES.DISTRICT, COUNT(RES.CONSTITUENCY) AS VOTESCOUNT
FROM voter_count RES
JOIN
(SELECT CONSTITUENCY, MAX(VOTES) AS VOTES
FROM voter_count
GROUP BY CONSTITUENCY) MAXS
USING (VOTES, CONSTITUENCY)
GROUP BY PARTYNAME,DISTRICT
Try below query
SELECT RES.PARTYNAME, RES.DISTRICT, COUNT( RES.CONSTITUENCY ) AS VOTESCOUNT
FROM voter_count RES
JOIN
(SELECT CONSTITUENCY, MAX(VOTES) AS VOTES
FROM voter_count
GROUP BY CONSTITUENCY) MAXS
USING (VOTES, CONSTITUENCY)
WHERE RES.DISTRICT = 'nagpur'
GROUP BY PARTYNAME, DISTRICT
I would like to get the data from one table, and count all results from other table, depending on the first table data, here is what I tried:
SELECT
cars.*, (
SELECT
COUNT(*)
FROM
uploads
WHERE
uploads.cid = cars.customer
) AS `count`,
FROM
`cars`
WHERE
customer = 11;
I dont really have an idea why its not working, as I'm not a regular MySQL user/coder...
Could anyone direct me in the right direction with this one?
SELECT
c.*, COUNT(u.cid) AS count
FROM
cars c
LEFT JOIN
uploads u
ON
u.cid=c.customer
WHERE
u.customer = 11;
GROUP BY c.cid
Try it by joining both tables using LEFT JOIN
SELECT a.customer, COUNT(b.cid) totalCount
FROM cars a
LEFT JOIN uploads b
ON a.customer = b.cid
WHERE a.customer = 11
GROUP BY a.customer
using COUNT(*) in LEFT JOIN will have records to have a minimum count of 1.
SELECT cars.*,COUNT(uploads.*) as uplloaded
from cars
left outer join uploads on uploads.cid = cars.customer
where cars.customer = 11
group by uploads.cid;
Try this :
SELECT customer, COUNT(cid) totalCount
FROM cars
INNER JOIN uploads
ON (customer = cid)
WHERE customer = 11
GROUP BY customer