I want to get all id with the max id2 value.
I tried just to get the max id2 but then it will looks for the overall maximum value of id2 inside the table , but i want to get all maxiums of id.
So I got 2 tables - table news and table topics.
Everytime I create a news there will automaticly create a topic. Now I want to show all news - and the current number of replies. So first step - topicid = id.
and every topic got id and id2.
id is the topic id
and id2 is the reply id
so if i got topic (a) with 4 comments it would look like
(id(1),id2(1))
(id(1),id2(2))
(id(1),id2(3))
(id(1),id2(4))
now a new topic (b) with 6 comments
(id(2),id2(1))
(id(2),id2(2))
(id(2),id2(3))
(id(2),id2(4))
(id(2),id2(5))
(id(2),id2(6))
so i want to get ((id(1),id2(4)) and (id(2),id2(6)))
<?php
$news = "SELECT n.titel,n.datum,n.typ_news,n.news,n.verfasser,n.time,n.topicid,
t.id, t.id2 FROM news n LEFT JOIN topics t ON t.id = n.topicid
ORDER BY n.id DESC LIMIT 10 ";
$neuenews = mysql_query($news);
while ($dnews = mysql_fetch_array($neuenews))
{
echo " <div style='text-align:center;color:#FFFFFF;font-size: 24px;'> "
.$dnews['titel'].
"a";
}
Ehm this was the solution :
$dn1 = mysql_query('select c.id, c.name, c.description, c.position,c.bild,
(select count(t.id) from topics as t where t.parent=c.id and t.id2=1) as topics,
(select count(t2.id) from topics as t2 where t2.parent=c.id and t2.id2!=1) as replies
from categories as c group by c.id order by c.position asc');
Try this:
SELECT n.titel,n.datum,n.typ_news,n.news,n.verfasser,n.time,n.topicid, t.id, MAX(t.id2) AS id2
FROM news n
LEFT JOIN
topics t
ON t.id = n.topicid
GROUP BY n.topicid
ORDER BY n.id DESC LIMIT 10
It looks like the specified/desired result from the topics table is accomplished by a query like this:
SELECT t.id
, MAX(t.id2) AS max_id2
FROM topics t
GROUP BY t.id
OPTION 1
To get that result joined to rows in news, you could use that query as an inline view in your query in place of the topics table. For example:
SELECT n.titel
, n.datum
, n.typ_news
, n.news
, n.verfasser
, n.time
, n.topicid
, t.id
, t.max_id2
FROM news n
LEFT
JOIN ( SELECT m.id
, MAX(m.id2) AS max_id2
FROM topics m
GROUP BY m.id
) t
ON t.id = n.topicid
ORDER BY n.id DESC LIMIT 10
OPTION 2
If id is UNIQUE (or PRIMARY KEY) in news table, then you may be able to eliminate the inline view, do a join to topics, and do a GROUP BY n.id, something like this:
SELECT n.titel
, n.datum
, n.typ_news
, n.news
, n.verfasser
, n.time
, n.topicid
, t.id
, MAX(t.id2) AS max_id2
FROM news n
LEFT
JOIN topics t
ON t.id = n.topicid
GROUP BY n.id
ORDER BY n.id DESC LIMIT 10
Not clear enough. what are the columns id= 1 id2=1 etc.? Two tables each with 2 columns? No clue.
I'm thinking something on the order but No clue what you actually want.
SELECT `MAX(`id2`) as MAX,`id` FROM `News` WHERE `id2` = `MAX`
Related
I am working on an sql query where I have three tables posts, users and comments. I want to display all posts with its users and number of comments on this. I have following query but it is giving me wrong result:
SELECT
c.userid, count(c.userid), p.postid
FROM comments c, posts p
where c.userid = p.userid group by c.userid
In addition to above query I also require firstname and lastname from users table.
Try something like this,
SELECT
u.userid, u.firstname, u.lastname,p.post, p.postid,
count(c.userid) totalcoments -- may be c.commentid
FROM users u
JOIN posts p ON p.userid=u.userid
LEFT JOIN comments c OM c.postid=p.postid
GROUP BY u.userid, u.firstname, u.lastname,p.post, p.postid
Try something like the following:
SELECT
postid
, p.userid
, COALESCE((
SELECT COUNT( * ) FROM comments WHERE postid = p.id
), 0 ) AS cnt_postid
, COALESCE( ( SELECT CONCAT( firstname, ' ', lastname ) FROM users WHERE userid = p.userid ), 'N/A' ) AS NAME
FROM posts p
LEFT JOIN comments c ON c.postid = p.id
GROUP BY postid
ORDER BY postid
you are probably getting the same amount of count because you not using a group by.
GROUP BY must always be used when using aggregate function. What the group by does is that it will select all unique posts and the the count will return the number of users for that one unique post
I have 2 tables(I'm making kind of forum) I would like to sort topics order by last post that has been written(order by row 'posts.date_written'). I was trying to do it by myself but I couldn't get it working.
Topic table:
ID|id_subforum|owner_id|owner|title|description
Posts table:
ID|id_subforum|id_topic|by|description|date_written
Can somebody show me how should this SQL look like?
SELECT t.*
FROM topics AS t
LEFT JOIN (
SELECT id_topic, id_subforum, MAX(date_written) AS last_date
FROM posts
GROUP BY id_topic, id_subforum
) AS p
ON t.id = p.id_topic AND t.id_subforum = p.id_subforum
WHERE t.id_subforum = '$forumId'
ORDER BY last_date DESC
I am stuck on one query in mysql.
I want to fetch most recent comment from the table
the comment should be most recent comment on the blog
the blogs should be latest 3 blogs.
display comment & blog only if their status is Enabled
records should be like this
Table Structure for the table the table blog
blog_id int - primary (auto increment)
blog_title -varchar
blog_desc -varchar
blog_image -varchar
blog_tags -varchar
tot_comments -int
blog_creater -varchar
blog_create_date -datetime
blog_status -enum ('Enable','Disable')
table structure for the table blog_comment
comment_id -int (auto increment)
fk_blog_id -int
comment -varchar
comment_by -varchar
email -varchar
comment_date -datetime
comment_status -enum ('Enable','Disable')
And below is query written by me, but the result I am getting is wrong.
SELECT b.blog_title,b.blog_image, bc.*
FROM blog_comments bc, blog b
WHERE bc.comment_status='Enable'
AND b.blog_status='Enable'
AND b.blog_id=bc.fk_blog_id
GROUP BY bc.fk_blog_id
ORDER BY bc.comment_date DESC
LIMIT 0,3
Output
for this the easy solution will be execute 2 query for your result . first query get blog post result
$db_blog="select blog_id,blog_title from blog where blog_ststus='Enable'";
$que=mysql_query($db_blog);
while($row=mysql_fetch_object($que))
{
echo $row->blog_title;
$db_comment="select comment from blog_comments where fk_blog_id=".$row->blog_id." and comment_status='Enable' order by comment_date desc";
$quec=mysql_query($db_comment);
while($comment=mysql_fetch_object($quec))
{
echo $comment->comment;
}
}
Try this:
SELECT * FROM blog_comments bc, blog b
WHERE `bc.comment_status`='Enable'
AND `b.blog_status`='Enable'
AND `b.blog_id`=bc.fk_blog_id
ORDER BY `bc.comment_date` DESC LIMIT 1;
Try a simpler one:
SELECT * FROM `blog_comment` WHERE 'blog_status'='Enable' AND 'blog_id'='$blogidherefromtitle' ORDER BY 'comment_date' DESC LIMIT1
SELECT b.blog_title,b.blog_image, bc.*
FROM blog b
left join (
Select * from
blog_comments bc
WHERE bc.comment_status='Enable'
GROUP BY bc.fk_blog_id
having max(bc.comment_date) = bc.comment_date
) bcc on b.blog_id=bcc.fk_blog_id
where
b.blog_status='Enable'
ORDER BY b.blog_create_date desc
LIMIT 0,3
Try this one
try
SELECT b.blog_title,b.blog_image, bc.*
FROM blog_comments AS bc, blog AS b
WHERE bc.comment_status='Enable'
AND b.blog_status='Enable'
AND b.blog_id=bc.fk_blog_id
GROUP BY bc.fk_blog_id
ORDER BY bc.comment_date DESC
LIMIT 0,3;
(I'm not 100% sure)
SELECT b.blog_title,b.blog_image, bc.*
FROM blog_comments bc JOIN blog b ON bc.fk_blog_id = b.blog_id
WHERE bc.comment_status='Enable'
AND b.blog_status='Enable'
GROUP BY bc.fk_blog_id
ORDER BY bc.comment_date DESC
LIMIT 0,3
select b.blog_title, b.blog_image, bc.*
from blog b join
(select bc.*
from bc join (select fk_blog_id, max(comment_date) latest_date
from blog_comment
where comment_status = 'Enable'
group by fk_blog_id) latest
on bc.fk_blog_id = latest.fk_blog_id and bc.comment_date = latest_date) c
on b.blog_id = c.fk_blog_id
where b.blog_status = 'Enable'
order by c.comment_date desc
limit 0, 3
The c subquery finds the row with the latest comment for each blog, using the technique in the linked question. This is then joined with the blog table to get the appropriate blog data.
Try this query
SELECT
bc.*
FROM
blog AS b
INNER JOIN (SELECT id , MAX(id) AS MaxID FROM blog) AS bl ON bl.id = b.id
LEFT JOIN blog_comment AS bc ON bc.fk_blog_id = b.id
ORDER BY bc.comment_id DESC
LIMIT 3
EDITS:
SELECT
bc.*
FROM
blog AS b
INNER JOIN (SELECT id , MAX(id) AS MaxID FROM blog GROUP BY id) AS bl ON bl.id = b.id
INNER JOIN (SELECT MAX(id) , fk_blog_id FROM blog_comment GROUP BY id) AS bc ON bc.fk_blog_id = b.id
ORDER BY bc.comment_id DESC
LIMIT 3
This is for 3 latest blogs and latest single comments for each blog
Here using inner join will fetch the latest blog. than join comments and order them with date or id and limit them according to your requirements.
I have 2 tables.
First:
TABLE Articles
ID
Second:
TABLE Viewcount
DATE DATE PK
ARTICLE_ID INT PK (MATCHES ID IN TABLE Articles)
NUMVIEWS INT
How do I select all IDs from table Articles and then order by NUMVIEWS (DESC) of Viewcount according to dates?
I then need to append the IDs from Articles that were not found in viewcount to the End of the results in no particular order.
I know it has to be some sort of Join but I can't figure it out..
try this
SELECT id from Articles a
LEFT JOIN Viewcount v
ON a.id = v.article_id
AND v.date = 'some date here'
ORDER BY v.numviews ,v.date desc
A simple join will suffice, yes:
SELECT a.id FROm Articles a LEFT JOIN Viewcount v
ON v.article_id = a.id
ORDER BY v.numviews desc, v.date
This should work:
SELECT * FROM `Articles` `a`, `Viewcount` `v`
WHERE `v`.`ARTICLE_ID`=`a`.`ID`
ORDER BY `v`.`NUMVIEWS` DESC
Replace SELECT * by SELECT `a`.`ID` to get only the Article IDs.
SELECT ID from (Articles JOIN Viewcount on Articles.ID = Viewcount.ID) ORDER BY Viewcount.NUMVIEWS, Viewcount.date
I have two tables called 'events' and 'topics' each table can have many comments.
What I need to do is list all the events and topics with the amount of comments for each row. I've managed to return all the topics, which works great but I don't know how I can add the events table to the MySql. The comments and events table fields are listed below. Can anyone help me with this query?
Events:
ID
Event_Name
Comments:
post_id <-- the releated id for either the events or topics table
table <-- The table that the row belongs to so either topics or events
SELECT
t.id, t.title, c.created_at,
IF(ISNULL(c.allComments), 0, c.allComments) AS totalComments
FROM topics AS t
LEFT OUTER JOIN (
SELECT created_at, post_id, COUNT(*) AS allComments
FROM comments
GROUP BY post_id
) AS c ON c.post_id = t.id
ORDER BY tc.created_at DESC, c.allComments DESC
Sounds like events and topics should be the same table.
Still, I think we can do this with a UNION. Events and Topics have the same columns i hope? (Or at least the same important ones?)
(SELECT c.table as event_or_topic, e.*, count(C.table), MAX(C.created_at) as latest_c
FROM events E LEFT JOIN comments C on (C.post_id = E.id)
WHERE C.table = 'Events'
GROUP BY C.post_id)
UNION
(SELECT c.table as event_or_topic, t.id*, count(C.table), MAX(C.created_at) as latest_c
FROM topics T LEFT JOIN comments C on (C.post_id = E.id)
WHERE C.table = 'Topics'
GROUP BY C.post_id)
ORDER BY latest_c
Notice that the ORDER BY applies to the whole UNION, not the individual SELECTs.
The use of LEFT JOIN should allow those rows without Comments to still show. I think the problem is that we have parts of our select dependent on comments (ie - C.table, ordering on last comment, etc). The count should be fine - will just be zero if there are no comments.
You might need to change the SELECT part slightly. I'd like to display C.table so you know whether a row is a topic or event, but im afraid it might screw up the count. Do you need anything from comments besides the count? You use some columns other than post_id and table in your query that you neglected to explain in your question.
You still have columns I don't know what they are, like Comment's zoneTable
Try this:
SELECT
t.id, t.title, c.created_at, COUNT(c.allComments) AS totalComments
FROM topics AS t LEFT JOIN comments c ON t.id=c.post_id
GROUP BY t.id ORDER BY tc.created_at DESC, c.allComments DESC
If I understand your question you have 3 tables:
-Events
-Topics
-Comments
If that is true something like this should extract all the data:
SELECT *
FROM events,topics
LEFT JOIN comments ON post_ID = ID
ORDER BY date DESC
Hope i'm along the right lines!
W.
I've got it working. If anyone knows of a better and an efficient way of doing this, then please let me know:
(SELECT t.id, t.title, tc.dateCreated AS commentDate,
IF(ISNULL(tc.allComments), 0, tc.allComments) AS totalComments,
t.LastActive as dateChanged
FROM Events AS t
LEFT OUTER JOIN (
SELECT MAX(created_at) AS dateCreated, post_id,
COUNT(*) AS allComments
FROM comments
GROUP BY post_id
) AS tc ON tc.post_id = t.id)
UNION
(SELECT t.id, t.title, tc.dateCreated AS commentDate,
IF(ISNULL(tc.allComments), 0, tc.allComments) AS totalComments,
t.LastActive as dateChanged
FROM topics AS t
LEFT OUTER JOIN (
SELECT MAX(created_at) AS dateCreated, post_id,
COUNT(*) AS allComments
FROM comments
GROUP BY post_id
) AS tc ON tc.post_id = t.id)
ORDER BY commentDate DESC, dateChanged DESC, totalComments DESC