SELECT enquiry.*,
(SELECT comm
from comments
where enquiry.id = comments.enquiryId
order by time DESC
) as comm
FROM enquiry
where id='110' AND cmpId='3'
when i want to execute more than one row by removing limit it say "subquery executes more than one row"
Please help
Your subquery is called a scalar subquery, meaning that it must have one column and at most one row. One simple method is to put the results in multiple rows, using JOIN:
SELECT e.*, c.comments
FROM enquiry e JOIN
comments c
ON e.id = c.enquiryId
where e.id = 110 AND e.cmpId = 3;
Or you can put the subquery in the from clause (as below), which is similar to join condition.
SELECT enquiry.*, comm.comm
FROM enquiry,
(SELECT comm
from comments
where enquiry.id = comments.enquiryId
order by time DESC
) as comm
where id='110' AND cmpId='3'
As the relation between enquiry & comments is 1 to many (as appears)
You need to add GROUP_CONCAT() functions to group all comments as follows:
SELECT enquiry.*,
(SELECT GROUP_CONCAT(comm)
from comments
where enquiry.id = comments.enquiryId
order by time DESC
) as comm
FROM enquiry
where id='110' AND cmpId='3'
Related
Afternoon folks,
I have had a good dig around and can't find the answer, so a good time to ask!
I'd like to select random rows from one table and then join into this random rows from another table where the ID that I have is the same. It would also be great to only select where I have an entry in the second table. I have tried all manner of sub-queries but am getting a bit lost. An inner join as read will do it but again with the randomness of it all!! Grrr...
SELECT
tracks.track_id,
cuttings.square_cutting,
cuttings.cutting_2,
cuttings.cutting_3,
cuttings.blog_text
FROM tbl_tracks tracks,
(SELECT
square_cutting,
cutting_2,
cutting_3,
blog_text
FROM
tbl_cuttings
WHERE track_id = tracks.track_id <-- wont find it, obviously!!
ORDER BY RAND()
LIMIT 1) cuttings
WHERE tracks.active = '1' ORDER BY RAND()
Thanks in advance for any help.
So:
I'd like random tracks showing
track id -> with random cuttings, of which there can be many but I just want 1.
It would then be ideal to only show a result if there is a cutting associated with that track.
Hope that helps.
I'm now trying to go a step further with this and order this by a RAND() seed as I'm now having to add in pagination. Only problem is that its not giving me back the same random list due to a given seed. Any Ideas?
SELECT
tracks.track_id,
cuttings.square_cutting,
cuttings.cutting_2,
cuttings.cutting_3,
cuttings.blog_text
FROM tbl_tracks tracks
INNER JOIN
(SELECT track_id,
square_cutting,
cutting_2,
cutting_3,
blog_text
FROM
tbl_cuttings
ORDER BY RAND()) cuttings ON tracks.track_id = cuttings.track_id
WHERE tracks.active = '1'
ORDER BY RAND(1)
LIMIT 0,4;
you could use an inner join
SELECT
tracks.track_id,
cuttings.square_cutting,
cuttings.cutting_2,
cuttings.cutting_3,
cuttings.blog_text
FROM tbl_tracks tracks
INNER JOIN
(SELECT track_id,
square_cutting,
cutting_2,
cutting_3,
blog_text
FROM
tbl_cuttings
ORDER BY RAND()
LIMIT 1) cuttings on cuttings.track_id = tracks.track_id
WHERE tracks.active = '1'
ORDER BY RAND()
I am running this query, and I am getting ** #1241 - Operand should contain 1 column(s)** error:
SELECT `forumCategories`.`id`, `forumCategories`.`name`, `forumCategories`.`order`, `forumCategories`.`description`, `forumCategories`.`date_created`, COUNT(forumPosts.forumCategory_id) as postCount,
(SELECT `forumPosts`.*, `forumChildPosts`.`id`, `forumChildPosts`.`forumPost_id`, COUNT(forumChildPosts.forumPost_id) as childCount FROM `forumChildPosts` LEFT JOIN `forumPosts` ON `forumPosts`.`id` = `forumChildPosts`.`forumPost_id` GROUP BY `forumPosts`.`id`) AS childCount
FROM `forumCategories`
LEFT JOIN `forumPosts` ON `forumCategories`.`id` = `forumPosts`.`forumCategory_id`
GROUP BY `forumCategories`.`id`
ORDER BY `forumCategories`.`order` DESC
I have 3 tables:
forumCategories
forumPosts | forumPosts.forumCategory_id = forumCategories.id
forumChildPosts | forumChildPosts.forumPosts_id = forumPosts.id
I want to count all posts for the forum category, and them I want to count all the child posts that belongs to that forum category. How can I do this?
You can't select several items with a subselect and then give them one name. Now you're getting everything from forumPosts, something from forumChildPosts etc and trying to put that into a single column, childCount. This is not allowed.
It might be enough to remove all other result columns from that select and only leave the count?
I couldn't try it, is that makes sense ? But you can't get nested results from mysql due to its limitation, MYSQL is a Matrix table.
SELECT `forumCategories`.`id`,
`forumCategories`.`name`,
`forumCategories`.`order`,
`forumCategories`.`description`,
`forumCategories`.`date_created`,
COUNT(forumPosts.forumCategory_id) AS postCount,
(SELECT COUNT(forumChildPosts.forumPost_id) AS childCount FROM `forumChildPosts` LEFT JOIN `forumPosts` ON `forumPosts`.`id` = `forumChildPosts`.`forumPost_id` GROUP BY `forumPosts`.`id`) AS childCount
FROM `forumCategories`
LEFT JOIN `forumPosts` ON `forumCategories`.`id` = `forumPosts`.`forumCategory_id`
GROUP BY `forumCategories`.`id`
ORDER BY `forumCategories`.`order` DESC
I have three tables named issue_details, nature_payments, and rci_records. Now I have this query which joins this three tables.
SELECT issue_details.issue_date AS Date,
issue_details.check_no AS Check_No,
payees.payee_name AS Name_payee,
nature_payments.nature_payment AS Nature_of_Payment,
issue_details.issue_amount AS Checks_issued,
issue_details.nca_balance AS Nca_balance
FROM
issue_details
INNER JOIN
nature_payments ON
issue_details.nature_id = nature_payments.nature_id
INNER JOIN
payees ON
issue_details.payee_id = payees.payee_id
ORDER BY Date Asc, Check_no ASC
On my column in Nca_balance, this is a computed differences of every issuances of check. But you may not know what really the process of how I got the difference but to make it simple, let's say that I have another query
that dynamically get also the difference of this nca_balance column. Here is the query:
SELECT r.*,
(#tot := #tot - issue_amount) as bank_balance
FROM (SELECT #tot := SUM(nca_amount) as nca_total FROM nca
WHERE account_type = 'DBP-TRUST' AND
year(issue_date) = year('2015-01-11') AND
month(issue_date) = month('2015-01-11')
)
vars CROSS JOIN issue_details r
WHERE r.account_type = 'DBP-TRUST' AND
r.issue_date = '2015-01-11'
ORDER BY r.issue_date, r.check_no
I know it you may not get my point but I just want to replace the first query of the line
issue_details.nca_balance AS Nca_balance
with my own computation on my second query.
Please help me combine those two query into a single query. Thanks
I need help with an advanced SQL-query (MSSQL 2000).
I have a table called Result that lists athletics 100 and 200 meter race-times. A runner can have several racetimes but I want to show only the best time from each runner at each event.
The Result-table contains five columns, Result_id, athlete_id, result_time, result_date, event_code. So athlete_id must be unique when I list the values and result_time must be the fastest (lowest) value. Also I want to be able to choose if event_code should be "= 1" or "= 2", since 100 and 200 meter resulttimes are mixed in the same table.
I asked a similiar question a few days ago, but without the event_code condition.
This is the answer we came up with.
select r.*
from result r
inner join (
select athelete_id, min(result_time) as FastestTime
from result
group by athelete_id
) rm on r.athelete_id = rm.athelete_id and r.result_time = rm.FastestTime
Any ideas how I can add the event_code condition to this snippet?
Try this:
select r.*
from result r
inner join (
select athelete_id, min(result_time) as FastestTime
from result
where event_code = 1
group by athelete_id
) rm on r.athelete_id = rm.athelete_id and r.result_time = rm.FastestTime
Include the event code in the output of the subquery. Then you can show all events at the same time or choose them in an outer where clause:
select r.*
from result r inner join
(select athlete_id, event_code, min(result_time) as FastestTime
from result
group by athlete_id, event_code
) rm
on r.athelete_id = rm.athlete_id and
r.result_time = rm.FastestTime and
r.event_code = rm.event_code
-- where event_code = xx
The last line is an optional WHERE clause in case you want just one event at a time.
Here's the situation:
In my database i have a table with threads, and a table with replies. Both have a Timestamp field.
Now i am developing a forum and wish to order threads in the following manner:
If the thread has replies, then: ORDER BY tblReply.Timestamp DESC
Else, the thread has no replies: ORDER BY tblThread.Timestamp DESC
I do not know how to combine these 2 in one statement.
My query as it is now:
SELECT `PK_ThreadID`, `Title`, `tblUsers`.`Username`, `tblThread`.`Date`, count(tblReply.FK_ThreadID) AS number_replies FROM (`tblThread`)
JOIN `tblUsers` ON `tblUsers`.`PK_UserID` = `tblThread`.`FK_UserID`
LEFT JOIN `tblReply` ON `tblReply`.`FK_ThreadID` = `tblThread`.`PK_ThreadID`
WHERE `isExpertQuestion` = 0 AND `isPublic` = 1
GROUP BY `PK_ThreadID`
ORDER BY max(tblReply.Date)` desc
//Here it only orders by reply date, so threads with no replies appear at the bottom
How do i achieve the ordering i want in this query?
Like this probably:
SELECT `PK_ThreadID`, `Title`,
`tblUsers`.`Username`,
`tblThread`.`Date`,
count(tblReply.FK_ThreadID) AS number_replies
FROM (`tblThread`)
JOIN `tblUsers` ON `tblUsers`.`PK_UserID` = `tblThread`.`FK_UserID`
LEFT JOIN `tblReply` ON `tblReply`.`FK_ThreadID` = `tblThread`.`PK_ThreadID`
WHERE `isExpertQuestion` = 0 AND `isPublic` = 1
GROUP BY `PK_ThreadID`
ORDER BY
CASE WHEN COUNT(tblReply.FK_ThreadID) > 0 THEN tblReply.Timestamp
WHEN COUNT(tblReply.FK_ThreadID) = 0 OR tblReply.FK_ThreadID IS NULL
THEN tblThread.Timestamp
END DESC