I have written an sql statement that besides all the other columns should return the number of comments and the number of likes of a certain post. It works perfectly when I don't try to get the number of times it has been shared too. When I try to get the number of time it was shared instead it returns a wrong number of like that seems to be either the number of shares and likes or something like that. Here is the code:
SELECT
[...],
count(CS.commentId) as shares,
count(CL.commentId) as numberOfLikes
FROM
(SELECT *
FROM accountSpecifics
WHERE institutionId= '{$keyword['id']}') `AS`
INNER JOIN
account A ON A.id = `AS`.accountId
INNER JOIN
comment C ON C.accountId = A.id
LEFT JOIN
commentLikes CL ON C.commentId = CL.commentId
LEFT JOIN
commentShares CS ON C.commentId = CS.commentId
GROUP BY
C.time
ORDER BY
year, month, hour, month
Could you also tell me if you think this is an efficient SQL statement or if you would do it differently? thank you!
Do this instead:
SELECT
[...],
(select count(*) from commentLikes CL where C.commentId = CL.commentId) as shares,
(select count(*) from commentShares CS where C.commentId = CS.commentId) as numberOfLikes
FROM
(SELECT *
FROM accountSpecifics
WHERE institutionId= '{$keyword['id']}') `AS`
INNER JOIN account A ON A.id = `AS`.accountId
INNER JOIN comment C ON C.accountId = A.id
GROUP BY C.time
ORDER BY year, month, hour, month
If you use JOINs, you're getting back one result set, and COUNT(any field) simply counts the rows and will always compute the same thing, and in this case the wrong thing. Subqueries are what you need here. Good luck!
EDIT: as posted below, count(distinct something) can also work, but it's making the database do more work than necessary for the answer you want to end up with.
Quick fix:
SELECT
[...],
count(DISTINCT CS.commentId) as shares,
count(DISTINCT CL.commentId) as numberOfLikes
Better approach:
SELECT [...]
, Coalesce(shares.numberOfShares, 0) As numberOfShares
, Coalesce(likes.numberOfLikes , 0) As numberOfLikes
FROM [...]
LEFT
JOIN (
SELECT commentId
, Count(*) As numberOfShares
FROM commentShares
GROUP
BY commentId
) As shares
ON shares.commentId = c.commentId
LEFT
JOIN (
SELECT commentId
, Count(*) As numberOfLikes
FROM commentLikes
GROUP
BY commentId
) As likes
ON likes.commentId = c.commentId
Related
I am trying to do a count on the same column having different status, how can i do it, i tried but i am running into bunch of issues
SELECT
distinct tblsmsgroups.GroupName,
tblsmsphones.PhoneNumber,
tblsmsphones.GroupID,
count(case when status = 1 then) as active
FROM
tblsmscustomers,
tblsmsgroups
INNER JOIN tblsmsphones
ON tblsmsgroups.groupID = tblsmsphones.GroupID
status = 1 then active how many, and status = 0 , then counts of how many, i am still stuck at the syntactical difference as to how can i do, any idea?
Well, if you want to add stuff up, you want a group by.
If you want to join tables, you want join -- never use commas for that purpose.
That suggest something like:
SELECT g.GroupName, p.PhoneNumber, p.GroupID,
SUM(status = 1) as active,
SUM(status = 0) as not_active
FROM tblsmsgroups g JOIN
tblsmsphones p
ON g.groupID = p.GroupID JOIN
tblsmscustomers c
ON c.customerID = p.customerID -- have to guess the JOIN condition here
GROUP BY g.GroupName, p.PhoneNumber, p.GroupID;
Note: Your question does not have enough information to understand the join conditions between the three tables; the above is a reasonable guess.
You probably want something like this:
SELECT
tblsmsgroups.GroupName,
tblsmsphones.PhoneNumber,
tblsmsphones.GroupID,
sum(status = 1) as active_count,
sum(status != 1) as inactive_count
FROM
tblsmscustomers ,
tblsmsgroups
INNER JOIN tblsmsphones ON tblsmsgroups.groupID = tblsmsphones.GroupID
GROUP BY GroupName, PhoneNumber, GroupID
I am trying to select the count of likes on a specific project. The idea i came up with is
CAST(count(uploads.ID in (SELECT uploadID from votes)) as decimal) as numberoflikes
this works but the query then only returns one thing.
Entire query
SELECT DISTINCT users.NAME AS username
,users.ID AS userID
,subjects.NAME AS subjectname
,uploads.TIME
,uploads.description
,uploads.NAME
,uploads.ID
,CASE
WHEN uploads.ID IN (
SELECT uploadID
FROM votes
WHERE userID = 2
)
THEN CAST(1 AS DECIMAL)
ELSE CAST(0 AS DECIMAL)
END AS liked
,CASE
WHEN uploads.ID IN (
SELECT uploadID
FROM bookmarks
WHERE userID = 2
)
THEN CAST(1 AS DECIMAL)
ELSE CAST(0 AS DECIMAL)
END AS bookmarked
,CAST(count(uploads.ID IN (
SELECT uploadID
FROM votes
)) AS DECIMAL) AS numberoflikes
FROM uploads
INNER JOIN subjects ON (subjects.ID = uploads.subjectID)
INNER JOIN users ON (users.ID = uploads.userID)
INNER JOIN uploadGrades ON (uploads.ID = uploadGrades.uploadID)
INNER JOIN grades ON (grades.ID = uploadGrades.gradeID)
WHERE uploads.active = 1
AND subjects.ID IN (
SELECT subjectID
FROM userSubjects
INNER JOIN users ON (users.ID = userSubjects.userID)
WHERE userSubjects.userID = 2
)
AND grades.ID IN (
SELECT userGrades.gradeID
FROM uploadGrades
INNER JOIN userGrades ON (uploadGrades.gradeID = userGrades.gradeID)
WHERE userGrades.userID = 2
)
ORDER BY uploads.trueRating DESC;
Lets try a reduce version of your query, That is the base to get better answers
I reduce the initial query to user and upload to start. Also remove the fields you already know how to calculate.
.
SELECT DISTINCT users.NAME AS username
,users.ID AS userID
,uploads.NAME
,uploads.ID
,CAST(count(uploads.ID IN (
SELECT uploadID
FROM votes
)) AS DECIMAL) AS numberoflikes
FROM uploads
INNER JOIN users ON (users.ID = uploads.userID)
WHERE uploads.active = 1
ORDER BY uploads.trueRating DESC;
Then add votes with LEFT JOIN to replace the SELECT in the COUNT that way if not match you will get NULL and as I say in my comment COUNT doesnt count NULL's
.
SELECT DISTINCT users.NAME AS username
,users.ID AS userID
,uploads.NAME
,uploads.ID
,CAST(count(votes.uploadID)) AS DECIMAL) AS numberoflikes
FROM uploads
INNER JOIN users ON (users.ID = uploads.userID)
LEFT JOIN votes ON (uploads.ID = votes.uploadID)
WHERE uploads.active = 1
ORDER BY uploads.trueRating DESC;
Try something like this...
SELECT users.name as username, users.ID as userID, subjects.name as subjectname,
uploads.time, uploads.description, uploads.name, uploads.ID,
count(userVotes.userId), count(bookmarksMade.userId),
FROM uploads
join subjects on(subjects.ID = uploads.subjectID)
join users on(users.ID = uploads.userID)
join uploadGrades on(uploads.ID = uploadGrades.uploadID)
join grades on(grades.ID = uploadGrades.gradeID)
left join (select userId, uploadId from votes where userId = 2) as userVotes on uploads.id = userVotes.uploadId
left join (select userId, uploadId from bookmarks where userId = 2) as bookmarksMade on uploads.id = bookmarksMade.uploadId
join userSubjects on subjects.id = userSubjects.subjectID
WHERE uploads.active = 1 AND
userSubjects.userID = 2
ORDER BY uploads.trueRating DESC;
But, I am leaving out the userGrades thing, because you are doing a funky join there that I don't really understand (joining two tables on something that looks like it is not the whole primary key on either table).
Anyway, you really need to go to something more like this or what Oropeza suggests in his answer. Get more direct about what you want. This query looks like a monster that has been growing and getting things added in with "IN" clauses, as you needed them. Time to go back to the drawing board and think about what you want and how to get at it directly.
count(uploads.ID in (SELECT uploadID from votes)) as numberoflikes
group by uploads.Id ORDER BY uploads.trueRating DESC
I managed to do it like this. If i added the group by then it split the numberoflikes into rows and returned more then one row. Thanks for the help!
I've created sqlfiddle to try and get my head around this http://sqlfiddle.com/#!2/21e72/1
In the query, I have put a max() on the compiled_date column but the recommendation column is still coming through incorrect - I'm assuming that a select statement will need to be inserted on line 3 somehow?
I've tried the examples provided by the commenters below but I think I just need to understand this from a basic query to begin with.
As others have pointed out, the issue is that some of the select columns are neither aggregated nor used in the group by clause. Most DBMSs won't allow this at all, but MySQL is a little relaxed on some of the standards...
So, you need to first find the max(compiled_date) for each case, then find the recommendation that goes with it.
select r.case_number, r.compiled_date, r.recommendation
from reporting r
join (
SELECT case_number, max(compiled_date) as lastDate
from reporting
group by case_number
) s on r.case_number=s.case_number
and r.compiled_date=s.lastDate
Thank you for providing sqlFiddle. But only reporting data is given. we highly appreciate if you give us sample data of whole tables.
Anyway, Could you try this?
SELECT
`case`.number,
staff.staff_name AS ``case` owner`,
client.client_name,
`case`.address,
x.mx_date,
report.recommendation
FROM
`case` INNER JOIN (
SELECT case_number, MAX(compiled_date) as mx_date
FROM report
GROUP BY case_number
) x ON x.case_number = `case`.number
INNER JOIN report ON x.case_number = report.case_number AND report.compiled_date = x.mx_date
INNER JOIN client ON `case`.client_number = client.client_number
INNER JOIN staff ON `case`.staff_number = staff.staff_number
WHERE
`case`.active = 1
AND staff.staff_name = 'bob'
ORDER BY
`case`.number ASC;
Check below query:
SELECT c.number, s.staff_name AS `case owner`, cl.client_name,
c.address, MAX(r.compiled_date), r.recommendation
FROM case c
INNER JOIN (SELECT r.case_number, r.compiled_date, r.recommendation
FROM report r ORDER BY r.case_number, r.compiled_date DESC
) r ON r.case_number = c.number
INNER JOIN client cl ON c.client_number = cl.client_number
INNER JOIN staff s ON c.staff_number = s.staff_number
WHERE c.active = 1 AND s.staff_name = 'bob'
GROUP BY c.number
ORDER BY c.number ASC
SELECT
case.number,
staff.staff_name AS `case owner`,
client.client_name,
case.address,
(select MAX(compiled_date)from report where case_number=case.number),
report.recommendation
FROM
case
INNER JOIN report ON report.case_number = case.number
INNER JOIN client ON case.client_number = client.client_number
INNER JOIN staff ON case.staff_number = staff.staff_number
WHERE
case.active = 1 AND
staff.staff_name = 'bob'
GROUP BY
case.number
ORDER BY
case.number ASC
try this
I am working on 2 problems for homework and after many hours I have just about solved them both, the last issue I have is that both of my queries are coming back with doubled numerical values instead of single.
Here is what I have:
SELECT SUM(P.AMT_PAID) AS TOTAL_PAID, C.CITATION_ID, C.DATE_ISSUED, SUM(V.FINE_CHARGED) AS TOTAL_CHARGED
FROM PAYMENT P, CITATION C, VIOLATION_CITATION V
WHERE V.CITATION_ID = C.CITATION_ID
AND C.CITATION_ID = P.CITATION_ID
GROUP BY C.CITATION_ID;
and my other one:
SELECT C.CITATION_ID, C.DATE_ISSUED, SUM(V.FINE_CHARGED) AS TOTAL_CHARGED, SUM(P.AMT_PAID) AS TOTAL_PAID, SUM(V.FINE_CHARGED) - SUM(P.AMT_PAID) AS TOTAL_OWED
FROM (CITATION C)
LEFT JOIN VIOLATION_CITATION V
ON V.CITATION_ID = C.CITATION_ID
LEFT JOIN PAYMENT P
ON P.CITATION_ID = C.CITATION_ID
GROUP BY C.CITATION_ID
ORDER BY TOTAL_OWED DESC;
I am sure there is just something that I am overlooking. If someone else could kindly tell me where I went awry it would be a great help.
Select Sum(P.Amt_Paid) As Total_Paid, C.Citation_Id
, C.Date_Issued, Sum(V.Fine_Charged) As Total_Charged
From Payment P
Join Citation C
On C.Citation_Id = P.Citation_Id
Join Violation_Citation V
On V.Citation_Id = C.Citation_Id
Group By C.Citation_Id
First, you should use the JOIN syntax instead of using the comma-delimited list of tables. It makes it easier to read, more standardized and will help prevent problems by overlooking a filtering clause.
Second, the most likely reason for having a sum that is too large is due to the join to the VIOLATION_CITATION table. If you remove the Group By and columns with aggregate functions, you will likely see that P.AMT_PAID is repeated for each instance of VIOLATION_CITATION. Perhaps, the following will solve the problem:
Select Coalesce(PaidByCitation.TotalAmtPaid,0) As Total_Paid
, C.Citation_Id, C.Date_Issued
, Coalesce(ViolationByCitation.TotalCharged,0) As Total_Charged
, Coalesce(ViolationByCitation.TotalCharged,0)
- Coalesce(PaidByCitation.TotalAmtPaid,0) As Total_Owed
From Citation As C
Left Join (
Select P.Citation_Id, Sum( P.Amt_Paid ) As TotalAmtPaid
From Payment As P
Group By P.Citation_Id
) As PaidByCitation
On PaidByCitation.Citation_Id = C.Citation_Id
Left Join (
Select V.Citation_Id, Sum( V.Find_Charged ) As TotalCharged
From Violation_Citation As V
Group By V.Citation_Id
) As ViolationByCitation
On ViolationByCitation.Citation_Id = C.Citation_Id
The use of Coalesce is to ensure that if the left join returns no rows for a given Citation_ID value, that we replace the Null with zero.
I'm having an odd problem with the following query, it works all correct,
the count part in it gets me the number of comments on a given 'hintout'
I'm trying to add a similar count that gets the number of 'votes' for each hintout, the below is the query:
SELECT h.*
, h.permalink AS hintout_permalink
, hi.hinter_name
, hi.permalink
, hf.user_id AS followed_hid
, ci.city_id, ci.city_name, co.country_id, co.country_name, ht.thank_id
, COUNT(hc.comment_id) AS commentsCount
FROM hintouts AS h
INNER JOIN hinter_follows AS hf ON h.hinter_id = hf.hinter_id
INNER JOIN hinters AS hi ON h.hinter_id = hi.hinter_id
LEFT JOIN cities AS ci ON h.city_id = ci.city_id
LEFT JOIN countries as co ON h.country_id = co.country_id
LEFT JOIN hintout_thanks AS ht ON (h.hintout_id = ht.hintout_id
AND ht.thanker_user_id = 1)
LEFT JOIN hintout_comments AS hc ON hc.hintout_id = h.hintout_id
WHERE hf.user_id = 1
GROUP BY h.hintout_id
I tried to add the following to the select part:
COUNT(ht2.thanks_id) AS thanksCount
and the following on the join:
LEFT JOIN hintout_thanks AS ht2 ON h.hintout_id = ht2.hintout_id
but the weird thing happening, to which I could not find any answers or solutions,
is that the moment I add this addtiional part, the count for comments get ruined (I get wrong and weird numbers), and I get the same number for the thanks -
I couldn't understand why or how to fix it...and I'm avoiding using nested queries
so any help or pointers would be greatly appreciated!
ps: this might have been posted twice, but I can't find the previous post
When you add
LEFT JOIN hintout_thanks AS ht2 ON h.hintout_id = ht2.hintout_id
The number of rows increases, you get duplicate rows for table hc, which get counted double in COUNT(hc.comment_id).
You can replace
COUNT(hc.comment_id) <<-- counts duplicated
/*with*/
COUNT(DISTINCT(hc.comment_id)) <<-- only counts unique ids
To only count unique appearances on an id.
On values that are not unique, like co.county_name the count(distinct will not work because it will only list the distinct countries (if all your results are in the USA, the count will be 1).
Quassnoi
Has solved the whole count problem by putting the counts in a sub-select so that the extra rows caused by all those joins do not influence those counts.
SELECT h.*, h.permalink AS hintout_permalink, hi.hinter_name,
hi.permalink, hf.user_id AS followed_hid,
ci.city_id, ci.city_name, co.country_id, co.country_name,
ht.thank_id,
COALESCE(
(
SELECT COUNT(*)
FROM hintout_comments hci
WHERE hc.hintout_id = h.hintout_id
), 0) AS commentsCount,
COALESCE(
(
SELECT COUNT(*)
FROM hintout_comments hti
WHERE hti.hintout_id = h.hintout_id
), 0) AS thanksCount
FROM hintouts AS h
JOIN hinter_follows AS hf
ON hf.hinter_id = h.hinter_id
JOIN hinters AS hi
ON hi.hinter_id = h.hinter_id
LEFT JOIN
cities AS ci
ON ci.city_id = h.city_id
LEFT JOIN
countries as co
ON co.country_id = h.country_id
LEFT JOIN
hintout_thanks AS ht
ON ht.hintout_id = h.hintout_id
AND ht.thanker_user_id=1
WHERE hf.user_id = 1