I have two sql tables one which has users and the other which has messages.
Right now my query is :
SELECT users.memberid,users.username,users.profileimage,users.gender,message.messagebody, message.fromid,message.toid,message.messageid
FROM message,users
WHERE message.fromid = users.memberid AND message.toid = '$id' AND recieverdeleted='0'
ORDER BY datetime DESC LIMIT 55
Right now what is being returned is all the information for everymessage regardless of formid(sender's id)
The thing is , I want to only display the most recent message for every from id ..Kind of like how Facebook only shows you the most recent message that friend x has sent you, and not all the messages. I will work on showing all messages after the user has clicked on his friend's most recent message.
Thanks
Well, you tried. That's good.
SELECT u.memberid
, u.username
, u.profileimage
, u.gender
, m.messagebody
, m.fromid
, m.toid
, m.messageid
FROM users u
JOIN message m
ON m.fromid = u.memberid
JOIN (SELECT fromid,toid,MAX(datetime) max_datetime FROM message GROUP BY fromid,toid) n
ON n.fromid = m.fromid
AND n.toid = m.toid
AND n.max_datetime = m.datetime
WHERE message.toid = $id
AND recieverdeleted = 0
ORDER
BY datetime DESC LIMIT 55;
At first join the two tables than apply order by because at this moment the command is not sure for which table you want to apply the ordering.
Or better you create an intermediate table from the selection of two tables and then apply the ordering.
Something like:
SELECT username,messagebody,fromid FROM(
SELECT users.memberid,users.username,users.profileimage,users.gender,message.messagebody, message.fromid,message.toid,message.messageid,message.datetime
FROM message,users
WHERE message.fromid = users.memberid AND message.toid = '$id' AND recieverdeleted='0' )INTERMEDIATE_TABLE ORDER BY datetime DESC
I might be wrong in syntax as I have done sql codes a long ago but you should try something very similar like this.
Try this its working
SELECT m1.*
FROM table_name m1
INNER JOIN (SELECT MAX(senddate) AS senddate,
IF(member_id2 = 3, member_id1, member_id2 ) AS user
FROM table_name
WHERE (member_id1 = 3 AND delete1=0) OR
(member_id2 = 3 AND delete2=0)
GROUP BY user) m2
ON m1.senddate = m2.senddate AND
(m1.member_id1 = m2.user OR m1.member_id2 = m2.user)
WHERE (member_id1 = 3 AND delete1=0) OR
(member_id2 = 3 AND delete2=0)
ORDER BY m1.senddate DESC
Try this::
SELECT users.memberid,users.username,users.profileimage,users.gender,message.messagebody, message.fromid,message.toid,message.messageid
FROM message inner join users on (message.fromid = users.memberid)
where message.toid = '$id' AND recieverdeleted='0'
ORDER BY message_datetime DESC limit 1
Related
review table has store_idx, user_idx etc...
I want to create a query sentence that gets information about the store to which the user has bookmarked with the user_id value entered.
The query sentence I made is
select A.store_name
, A.store_img
, count(B.store_idx) as review_cnt
from board.store A
Left
Join board.review B
On A.store_idx is B.store_idx
where store_idx is (select A.store_idx from bookmark where user_id = ?)
However, nothing came out as a result.
Help me..
Please use below Query:
SELECT store_name
, store_img
, SUM(review_cnt) AS review_cnt
FROM
( SELECT DISTINCT A.store_name
, A.store_img
, CASE WHEN B.store_idx IS NULL THEN 0 ELSE 1 END AS review_cnt
FROM bookmark br
JOIN board.store A
ON A.store_idx = br.store_idx
LEFT
JOIN board.review B
ON A.store_idx = B.store_idx
WHERE br.user_id = ?
)T
The WHERE clause is obviously filtering out all rows. We can't do much about that. But your query is also lacking a GROUP BY, the table aliases can be improved, and the join condition is not correct.
So, try this version:
select s.store_name, s.store_img, count(b.store_idx) as review_cnt
from board.store s left join
board.review r
on s.store_idx = r.store_idx
where b.store_idx in (select b.store_idx
from bookmark b
where b.user_id = ?
);
I have a MYSQL query I'm working on that pulls data from multiple joins.
select students.studentID, students.firstName, students.lastName, userAccounts.userID, userstudentrelationship.userID, userstudentrelationship.studentID, userAccounts.getTexts, reports.pupID, contacts.pfirstName, contacts.plastName, reports.timestamp
from userstudentrelationship
join userAccounts on (userstudentrelationship.userID = userAccounts.userID)
join students on (userstudentrelationship.studentID = students.studentID)
join reports on (students.studentID = reports.studentID)
join contacts on (reports.pupID = contacts.pupID)
where userstudentrelationship.studentID = "10000005" AND userAccounts.getTexts = 1 ORDER BY reports.timestamp DESC LIMIT 1
I have a unique situation where I would like one of the joins (the reports join) to be limited to the latest result only for that table (order by reports.timestamp desc limit 1 is what I use), while not limiting the result quantities for the overall query.
By running the above query I get the data I would expect, but only one record when it should return several.
My question:
How can I modify this query to ensure that I receive all possible records available, while ensuring that only the latest record from the reports join used? I expect that each record will possibly contain different data from the other joins, but all records returned by this query will share the same report record
Provided I understand the issue; one could add a join to a set of data (aliased Z below) that has the max timestamp for each student; thereby limiting to one report record (most recent) for each student.
SELECT students.studentID
, students.firstName
, students.lastName
, userAccounts.userID
, userstudentrelationship.userID
, userstudentrelationship.studentID
, userAccounts.getTexts
, reports.pupID
, contacts.pfirstName
, contacts.plastName
, reports.timestamp
FROM userstudentrelationship
join userAccounts
on userstudentrelationship.userID = userAccounts.userID
join students
on userstudentrelationship.studentID = students.studentID
join reports
on students.studentID = reports.studentID
join contacts
on reports.pupID = contacts.pupID
join (SELECT max(timestamp) mts, studentID
FROM REPORTS
GROUP BY StudentID) Z
on reports.studentID = Z.studentID
and reports.timestamp = Z.mts
WHERE userstudentrelationship.studentID = "10000005"
AND userAccounts.getTexts = 1
ORDER BY reports.timestamp
for get all the records you should avoid limit 1 at the end of the query
for join anly one row from reports table you could use subquery as
select
students.studentID
, students.firstName
, students.lastName
, userAccounts.userID
, userstudentrelationship.userID
, userstudentrelationship.studentID
, userAccounts.getTexts
, t.pupID
, contacts.pfirstName
, contacts.plastName
, t.timestamp
from userstudentrelationship
join userAccounts on userstudentrelationship.userID = userAccounts.userID
join students on userstudentrelationship.studentID = students.studentID
join (
select * from reports
order by reports.timestamp limit 1
) t on students.studentID = t.studentID
join contacts on reports.pupID = contacts.pupID
where userstudentrelationship.studentID = "10000005"
AND userAccounts.getTexts = 1
I have the following Database Design:
Database Design
I want to get all Information from table 'info' where the id IS NOT in table 'archived'. To do so I wrote:
SELECT *
FROM traffic_info i
LEFT JOIN
traffic_info_archived a ON (i.info_id = a.info_id)
WHERE
i.branch_id = 4 AND i.user_id = 7 a.info_id IS NULL ORDER BY i.info_date_from ASC
This works as expected.
The next challenge is to only show information that are also included in the 'published' table. To get this done I have expanded my previous query to :
SELECT *
FROM traffic_info i
LEFT JOIN
traffic_info_archived a ON (i.info_id = a.info_id)
RIGHT JOIN
traffic_info_publised p ON (i.info_id = p.info_id)
WHERE
i.branch_id = 4 AND a.info_id AND i.user_id = 7 IS NULL ORDER BY i.info_date_from ASC
This does also work as expected.
The final challenge is to Order this result according to table 'read'. Information´s id that are NOT in table 'read' should be ordered ASC. But even if its id does not appear in table 'read' they should not be excluded from the query output. BUT the primary ORDER should be
i.info_date_from ASC
I hope this is understandable, my English is not the best :) If not, please comment and I will do my best to make it understandable. Hope some can help!
I´ve tried to create a SQLFiddle, but I wasn´t able to create a runnable example, sorry for that.
UPADTE:
Using the approach from #Dylan Su
SELECT *
FROM traffic_info i
LEFT JOIN
traffic_info_archived a ON (i.info_id = a.info_id)
INNER JOIN
traffic_info_publised p ON (i.info_id = p.info_id)
WHERE
i.branch_id = 4 AND a.info_id AND i.user_id = 7 IS NULL
ORDER BY
CASE WHEN NOT EXISTS(SELECT 1 FROM read WHERE i.info_id = read.info_id)
THEN i.info_date_from END ASC;
the goal is nearer then it ever was :)
Sample Data output
Both entries marked with a red "X" are in table read. Therefore id 3 should be last the, in the middle 1 and 2 at the top.
So the last thing to archive is to do the correct order of table read. I´ve tried sth like:
(SELECT 1 FROM traffic_info_read WHERE i.info_id = traffic_info_read.info_id ORDER BY traffic_info_read.info_id DESC)
But that didn´t had any influnce.
Try this:
SELECT *
FROM traffic_info i
LEFT JOIN
traffic_info_archived a ON (i.info_id = a.info_id)
INNER JOIN
traffic_info_publised p ON (i.info_id = p.info_id)
WHERE
i.branch_id = 4 AND a.info_id AND i.user_id = 7 IS NULL
ORDER BY
EXISTS(SELECT 1 FROM read WHERE i.info_id = read.info_id) ASC,
i.info_date_from ASC;
The Answer of #Dylan Su is absolutely correct and I won´t unmark it as accepted.
However, based on the Information I gained from the conversation I have created another solution, that doesn´t make use of sub query.
I heard that using just JOIN´s will result in better performance, I don´t know if it´s correct and I don´t have that much test data currently to find out, but here is the solution using no sub query.
SELECT *
FROM traffic_info i
LEFT JOIN
traffic_info_archived a ON (i.info_id = a.info_id)
INNER JOIN
traffic_info_published p ON (i.info_id = p.info_id)
LEFT JOIN
traffic_info_read r ON (i.info_id = r.info_id)
WHERE
i.branch_id = 4 AND a.info_id IS NULL ORDER BY r.info_id IS NULL DESC, i.info_date_from ASC
;
I have a table with news items, I have another table with media_types, I want to make one simple query that reads the media_types table and count for each record how many news_items exist.
The result will be turned into a json response that I will use for a chart, this is my SQLstatement
SELECT
gc.country AS "country"
, COUNT(*) AS "online"
FROM default_news_items AS ni
JOIN default_news_item_country AS nic ON (nic.id = ni.country)
JOIN default_country AS c ON (nic.country = c.id)
JOIN default_geo_country AS gc ON (gc.id = c.geo_country)
LEFT JOIN default_medias ON (m.id = ni.media)
WHERE TRUE
AND ni.deleted = 0
AND ni.date_item > '2013-10-23'
AND ni.date_item < '2013-10-29'
AND gc.country <> 'unknown'
AND m.media_type = '14'
GROUP BY gc.country
ORDER BY `online` desc LIMIT 10
This is the json respond I create from the mysql respond
[
{"country":"New Zealand","online":"7"},
{"country":"Switzerland","online":"1"}
]
How do I add print and social data to my output like this
I would like the json respond look like this
[
{"country":"New Zealand","online":"7", "social":"17", "print":"2"},
{"country":"Switzerland","online":"1", "social":"7", "print":"1"}
]
Can I use the count (*) in the select statement to do something like this
COUNT( * ) as online, COUNT( * ) as social, COUNT( * ) as print
Is it possible or do I have to do several SQL statement to get the data I'm looking for?
This is the general structure:
SELECT default_geo_country.country as country,
SUM(default_medias.media_type = 14) as online,
SUM(default_medias.media_type = XX) as social,
SUM(default_medias.media_type = YY) as print
FROM ...
JOIN ...
WHERE ...
GROUP BY country
I think you want conditional aggregation. Your question, however, only shows the online media type.
Your query would be more readable by using table aliases and removing the back quotes. Also, if media_type is an integer, then you should not enclose the constant for comparison in single quotes -- I, for one, find it misleading to compare a string constant to an integer column.
I suspect this is the way you want to go. Where the . . . is, you want to fill in with the counts for the other media types.
SELECT default_geo_country.country as country,
sum(media_type = '14') as online,
sum(default_medias.media_type = XX) as social,
sum(default_medias.media_type = YY) as print
. . .
FROM default_news_items ni JOIN
default_news_item_country nic
ON nic.id = ni.country JOIN
default_country dc
ON nic.country = dc.id JOIN
default_geo_country gc
ON gc.id = dc.geo_country LEFT JOIN
default_medias dm
ON dm.id = dni.media
WHERE ni.deleted = '0'
AND ni.date_item > '2013-10-23'
AND ni.date_item < '2013-10-29'
AND gc.country <> 'unknown'
GROUP BY gc.country
ORDER BY online desc
LIMIT 10
I have a query like below...
SELECT
contents.id, contents.title, contents.createdBy,
(SELECT userGroup FROM suser_profile WHERE userId =
(SELECT users.id
FROM
users
WHERE
login = contents.createdBy)
) as userGroupID
FROM
contents
WHERE
contents.id > 0
AND contents.contentType = 'News'
**AND userGroupID = 3**
LIMIT 0, 10
When I try to assign the userGroupID inside WHERE clause the SQL fires an error saying SQL Error(1054):Unknown column "userGroupID" in "where clause"
meantime, if I make little changes like below,,
SELECT
contents.id, contents.title, contents.createdBy
FROM
smart_cms_contents
WHERE
contents.id > 0
AND contents.contentType = 'News'
**AND (SELECT userGroup FROM user_profile WHERE userId =
(SELECT users.id
FROM
users
WHERE
users.login = contents.createdBy)
) = 3**
LIMIT 0, 10
then the query works fine.
I have to use multiple userGroupID checking so that, 2nd style will make the query big, I have to have an style like first one, any help appreciated.
*NOTE : Table names are not original name what I am using in my project. You may ignore it if there are mistakes in table name. My main concern is on using the values assign to a variable by AS inside the WHERE clause.
Ignore the STARS in query*
use HAVING. example:
WHERE
contents.id > 0
AND
contents.contentType = 'News'
HAVING
userGroupID = 3
LIMIT 0, 10
If I'm understanding your initial query properly, then I believe what you want to do is a join:
SELECT DISTINCT
contents.id, contents.title, contents.createdBy
FROM
contents INNER JOIN users
ON contents.createdBy = users.login
INNER JOIN user_profile
ON user_profile.userId = users.id
WHERE
contents.id > 0
AND contents.contentType = 'News'
AND user_profile.userGroupID = 3
LIMIT 0, 10
Totally not the answer to the question you asked, but...
SELECT DISTINCT c.id, c.title, c.createdBy, s.userGroup AS userGroupID
FROM contents AS c
INNER JOIN users AS u
ON c.createdBy = u.login
INNER JOIN suser_profile AS s
ON s.userId = u.id
WHERE c.id > 0
AND c.contentType = 'News'
AND s.userGroup = 3