Inner join or other equal solution - mysql

I have good working sql query but I need to select also atribute from table advert. I tried with inner join but it wasn't successful. So this query is ok but I need to select one atribute from table advert.
SELECT D.* FROM details
WHERE (D.name LIKE ?) AND (D.id_advert IN(
SELECT A.id
FROM advert A
WHERE A.status=1 and duration >= CURDATE()
ORDER BY duration DESC ))

You can change the in (subquery ) in a proper inner join and the is simple use the columns form table A
SELECT D.* , A.*
FROM details
INNER JOIN advert A ON D.id_advert = A.id
AND A.status=1
AND duration >= CURDATE()
WHERE D.name LIKE ?

SELECT *
FROM details D
INNER JOIN advert A ON D.id_advert = A.id
INNER JOIN place P ON A.id_place = P.id
WHERE (D.NAME LIKE ?)
AND ( D.id_advert IN (
SELECT A.id
FROM advert A
WHERE A.STATUS = 1 AND duration >= CURDATE()
ORDER BY duration DESC
)
)
Here "?" is for search key. This query work perfect.

Related

Multiple inner-join statements combined with subquery

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

MySQL order by date before selecting

I'm trying to get all topics along with the last comment in each topic. I've tried a couple of different sql statements, which haven't been working out.
SELECT
a.*,
b.*,
c.*,
(SELECT COUNT(*) FROM comments WHERE comment_topic_id = a.topic_id) AS count
FROM topics AS a
LEFT JOIN categories AS b ON a.topic_category = b.category_id
LEFT JOIN (
SELECT *
FROM comments
ORDER BY comment_date DESC
) AS c ON a.topic_id = c.comment_topic_id
WHERE b.category_id = '1' AND b.category_permission <= '2'
ORDER BY a.topic_created ASC
The above code will generate a result for each comment instead of the most recent.
Any help is appreciated, I can provide images to illustrate the database and table structures
I've changed the alias of your count because count is a reserved word.
Try this:
EDIT
SELECT
a.*,
b.*,
co.*,
(SELECT COUNT(*) FROM comments WHERE comment_topic_id = a.topic_id) AS tot_comment
FROM topics AS a
JOIN categories AS b ON a.topic_category = b.category_id
LEFT JOIN (
SELECT *
FROM comments c
WHERE NOT EXISTS(
SELECT 'NEXT'
FROM comments c2
WHERE c2.comment_topic_id = c.comment_topic_id
AND c2.comment_date > c.comment_date
)
) AS co ON a.topic_id = co.comment_topic_id
WHERE b.category_id = '1' AND b.category_permission <= '2'
ORDER BY a.topic_created ASC

SQL join left get MAX(date)

i have these tables :
notice
id INT
cdate DATETIME
...
theme
id
name
notice_theme
id_notice
id_theme
I want to get the latest notices for each theme.
SELECT id_theme, n.id
FROM notice_theme
LEFT JOIN (
SELECT id, cdate
FROM notice
ORDER BY cdate DESC
) AS n ON notice_theme.id_notice = n.id
GROUP BY id_theme
The result is not good. An idea ? Thanks.
There are so many ways to solve this but I'm used to do it this way. An extra subquery is needed to separately calculate the latest cDate for every ID.
SELECT a.*, c.*
FROM theme a
INNER JOIN notice_theme b
ON a.ID = b.id_theme
INNER JOIN notice c
ON b.id_notice = c.ID
INNER JOIN
(
SELECT a.id_theme, MAX(b.DATE_CREATE) max_date
FROM notice_theme a
INNER JOIN notice b
ON a.ID_Notice = b.ID
GROUP BY a.id_theme
) d ON b.id_theme = d.id_theme AND
c.DATE_CREATE = d.max_date
SQLFiddle Demo

Modifying MYSQL query to get a JOIN between two tables

I'm breaking my head trying to modify this query(thx sgeddes) in order to
get at result not only from db_events.events fields, instead join it with some db_system.devices fields
SELECT e.*
FROM db_events.events e
JOIN (
SELECT Max(id) MaxId, device_id
FROM db_events.events
GROUP BY device_id ) e2 on e.Id = e2.MaxId AND e.device_id = e2.device_id
WHERE e.device_id IN (
SELECT device_id
FROM db_system.devices
WHERE vendor = 1)
ORDER BY e.id DESC
How can I get it without repeat the subquery:
SELECT *
FROM db_system.devices
WHERE vendor = 1
I need get db_system.devices.brand and db_system.devices.model joined with final results, and
I tried to modify it step to step, I tried with temporary tables, I suspect it should be something simple, but I have not been able to do it, of course thank you very much...
is this what you want?
SELECT e.*, a.*
FROM db_events.events e
INNER JOIN
(
SELECT Max(id) MaxId, device_id
FROM db_events.events
GROUP BY device_id
) e2 on e.Id = e2.MaxId AND
e.device_id = e2.device_id
INNER JOIN db_system.devices a
ON e.device_id = a.device_id AND
a.vendor = 1
ORDER BY e.id DESC
the condition a.vendor = 1 can also be moved on WHERE clause and the result is still the same since you are using INNER JOIN
SELECT ....
FROM .... JOIN ....
WHERE a.vendor = 1
ORDER BY ...

GROUP_CONCAT multiple values from table

I just added a table which holds a url and description for each item in place. The below query works ok ... but it's only returning the url and I need the desc also. I m not sure how to make this work.
$query_str = "SELECT a.userid, a.cat, a.id, a.name, a.image,
a.desc, a.country, b.user_id, c.username,
c.fbook, d.cat_id,
(
SELECT GROUP_CONCAT(url)
FROM one_add o
WHERE a.id=o.one_id
) AS url,
(
SELECT COUNT(id)
FROM one_msg m
WHERE m.guest_id = ? AND
m.one_id=a.id
) AS count
FROM place a
LEFT OUTER JOIN wait b
ON a.id=b.post_id AND
b.user_id= ?
JOIN users c
ON a.userid=c.id
LEFT JOIN (
SELECT userid, user_id,
GROUP_CONCAT( cat_id ) AS cat_id
FROM user_cat
WHERE userid='$user_id'
GROUP BY user_id
) AS d ON d.userid='$user_id' AND
d.user_id=a.userid
WHERE a.cat != ? ORDER BY a.date desc";
This is what I want to accomplish: desc
You can achibe this by using CONCAT inside GROUP_CONCAT function as:
(SELECT GROUP_CONCAT(CONCAT('',desc,''))
FROM one_add o
WHERE a.id=o.one_id) AS url
full query:
(SELECT COUNT(id) FROM one_msg m WHERE m.guest_id = ? AND m.one_id=a.id ) AS count
FROM place a
LEFT OUTER JOIN wait b ON a.id=b.post_id AND b.user_id= ?
JOIN users c ON a.userid=c.id
LEFT JOIN ( SELECT userid, user_id, GROUP_CONCAT( cat_id ) AS cat_id FROM user_cat WHERE userid='$user_id' GROUP BY user_id ) AS d ON d.userid='$user_id' AND d.user_id=a.userid
WHERE a.cat != ? ORDER BY a.date desc";