I have this MySQL query, seems pretty easy:
SELECT users.nick, users.id, COUNT(pm.id) AS pms
FROM users LEFT JOIN pm ON users.id = pm.touser
WHERE users.id = :id AND pm.read = 0
GROUP BY users.id
What I want to do here is simply count all the PMs that aren't read (doesn't have "1" in "read" col). If there are any, query works fine, but when there isn't any row meeting that condition, it returns nothing.
I spent the last hour looking for solution, but it seems really odd, that it works this way. It should only print "0" while echoing "pms".
Simply:
SELECT users.nick, users.id, COUNT(pm.id) AS pms
FROM users LEFT JOIN pm ON (users.id = pm.touser AND pm.read = 0)
WHERE users.id = :id
GROUP BY users.id;
Try this
SELECT nick,id, COUNT(id) AS pms
FROM users LEFT JOIN (Select touser as id from pm where read =0) as pms1
WHERE id = :id GROUP BY id
Try reversing the table order:
SELECT users.nick, users.id, COUNT(pm.id) AS pms
FROM pm
LEFT JOIN users
ON users.id = pm.touser
WHERE users.id = :id AND pm.read = 0
GROUP BY users.id
SELECT users.nick, users.id, COUNT(pm.id) AS pms
FROM users
LEFT JOIN
pm
ON (pm.touser, pm.read) = (users.id, 0)
WHERE users.id = :id
GROUP BY
users.id
pm.read = 0 should go to the ON clause.
WHERE clause filters out all NULL values resulting from the pm miss.
Related
I have 2 tables .. 1- users,,2-messages
I wrote this query but it doesn't show the last subject and I need last subject
select (
CASE WHEN messages.sender = 68314 THEN messages.receiver ELSE messages.sender END
) AS user_id,
MAX(messages.added) last_added,messages.subject,
MAX(messages.id) as last_id,users.username
FROM messages
INNER JOIN users ON users.id = IF(messages.sender = 68314, messages.receiver, messages.sender)
WHERE (messages.sender = 68314 or messages.receiver = 68314) AND messages.sender!=0
GROUP BY
(
CASE WHEN messages.sender = 68314 THEN messages.receiver ELSE messages.sender END
)
ORDER BY last_added DESC
It shows first subject, not the last one.
please give this query a try. It first select max(id) of messages of people talking to id 68314 assuming those are created last...and joins back with messages, and the joined with users to get the other person's name.
SELECT last_messages.user_id,
m.added as last_added,
m.subject,
last_messages.last_id,
u.username
FROM messages m
INNER JOIN
(SELECT IF(sender = 68314,receiver,sender) as user_id,
MAX(id) as last_id
FROM messages
WHERE IF(sender = 68314,sender,receiver) = 68314
GROUP BY user_id
)last_messages
ON last_messages.last_id = m.id
INNER JOIN users u ON last_messages.user_id = u.id
ORDER by last_added;
sqlfiddle
I'm hosting a platform where users get SQL logs, I want to make some kind of highscore for it so there like a top 10 of users who got the most logs.
All registered users get their own 'ID', in the logs the user 'ID' is displayed as: 'id'. So in users 'ID' is in capitals and in 'logs' it is without capitals.
I would like to have some kind of query like this:
SELECT username,ID FROM users ORDER BY COUNT (id) FROM logs LIMIT 10;
But this does not work so maybe someone of you have a solution?
Try this, you'll need to join the table and use the group function, really useful for what you're trying to achieve:
SELECT users.username, users.id
FROM users
LEFT JOIN logs on users.id = logs.id
GROUP BY users.id
ORDER BY COUNT (logs.id)
LIMIT 10;
Or try with aliases:
SELECT users.username as u, users.id as i
FROM users
LEFT JOIN logs on users.id = logs.id
GROUP BY i
ORDER BY COUNT (logs.id)
LIMIT 10;
Try this to achieve the log count:
SELECT users.username, users.id, COUNT(logs.id) as quantity
FROM users
LEFT JOIN logs on users.id = logs.id
GROUP BY users.id
ORDER BY COUNT(logs.id)
LIMIT 10;
Simple Inner Join should work
SELECT U.username,U.ID
FROM users U
INNER JOIN logs L
on U.id = L.id
Group by U.username,U.ID
ORDER BY COUNT (id) FROM LIMIT 10
SELECT User.username, User.ID, Count(Log.id) LogCount
FROM users User
LEFT JOIN logs Log
ON User.ID = Log.id
GROUP BY User.ID, User.username
ORDER BY LogCount DESC
LIMIT 10
The following statement gets row counts for user_ids from various tables/conditions where the users are within specific computers of a specific account. It works as expected. An example output would be something like this :
Array
(
[0] => Array
(
[computer_name] => COMPUTER_1
[username] => Steve
[t1count] => 13
[t2count] =>
[t3count] => 23
[t4count] => 64
)
... and so on for each
the statement :
$stmt = $db->prepare("
SELECT c.computer_name, users.username, t1count, t2count, t3count, t4count
FROM
( SELECT account_id, computer_id, computer_name
FROM computers
WHERE account_id = ".$_SESSION['user']['account_id']."
ORDER BY computer_id ASC LIMIT 0, ".$_SESSION['user']['licenses']."
) as c
LEFT JOIN users
on users.computer_id = c.computer_id
LEFT JOIN
(SELECT user_id, COUNT(user_id) as t1count
FROM t1
WHERE t1.title LIKE 'started'
GROUP BY user_id) as t_t1
on t_t1.user_id = users.user_id
LEFT JOIN
(SELECT user_id, COUNT(user_id) as t2count
FROM t2
GROUP BY user_id) as t_t2
on t_t2.user_id = users.user_id
LEFT JOIN
(SELECT user_id, COUNT(user_id) as t3count
FROM t1
WHERE t1.title LIKE 'blocked'
GROUP BY user_id) as t_t3
on t_t3.user_id = users.user_id
LEFT JOIN
(SELECT user_id, COUNT(user_id) as t4count
FROM t1
WHERE t1.title LIKE 'closed'
GROUP BY user_id) as t_t4
on t_t4.user_id = users.user_id
... and so on for each
WHERE c.account_id = ?
");
I want to also return a totalsum = t1count + t2count + t3count + t4count in this statement as well, but can't seem to get anything working. In this situation I cannot do outside processing (adding the values that are returned)... it needs to be in the statement. I am also open to any suggestions in what I already have if there are better options.
What are you trying to do with these values? SUM(t1count,t2count,t3count,t4count) AS totalsum should work to get a count of counts.
Your query is a bit hard to read. You have implicit and explicit JOINs. You are grouping numerous times and pulling columns when you can generally do this all in one shot. If you share an SQLFiddle, I will be able to clean this up, but in short:
SELECT
c.computer_name,
users.username,
count(t_t1.user_id) AS t1count,
count(t_t2.user_id) AS t2count,
count(t_t3.user_id) AS t3count,
count(t_t4.user_id) AS t4count,
(count(t_t1.user_id)+count(t_t2.user_id)+count(t_t3.user_id)+count(t_t4.user_id)) AS totalsum FROM users
LEFT JOIN computers AS c ON users.computer_id=c.computer_id AND c.account_id=?
LEFT JOIN t1 AS t_t1 ON t_t1.user_id = users.user_id AND t_t1.title LIKE "started"
LEFT JOIN t2 AS t_t2 ON t_t2.user_id = users.user_id
LEFT JOIN t1 AS t_t3 ON t_t3.user_id = users.user_id AND t_t3.title LIKE 'blocked'
LEFT JOIN t1 AS t_t4 ON t_t4.user_id = users.user_id AND t_t4.title LIKE 'closed'
WHERE c.account_id = ?
AND t_t1.title LIKE started
GROUP BY users.user_id;
This may need tweaking, as I stated, but it is a lot cleaner and easier to read and should accomplish something very similar.
Alternately, if you can't get the query to run the way you want it to when you change it to entirely explicit joins, rather than using SUM, try adding the values together like I did in the example above. It should prevent them from aggregating in the same way.
EDIT
After viewing your SQLFiddle, I have doctored up a solution which does away with nested queries. The positive is that it is cleaner. The negative is that it requires you to specify the users using an IN clause.
SELECT computers.account_id,computers.computer_id,computers.computer_name,users.user_id,users.username,count(distinct t_count1.log_id) AS count1,count(distinct t_count2.log_id) AS count2,count(distinct t_count3.log_id) AS count3, count(distinct t_count4.event_id) AS count4,
(count(distinct t_count1.log_id) + count(distinct t_count2.log_id) + count(distinct t_count3.log_id) + count(distinct t_count4.event_id)) AS totalcount
FROM users
INNER JOIN computers ON computers.computer_id=users.computer_id
LEFT JOIN logs AS t_count1 ON t_count1.type LIKE 'type1' AND t_count1.user_id=users.user_id
LEFT JOIN logs AS t_count2 ON t_count2.type LIKE 'type2' AND t_count2.user_id=users.user_id
LEFT JOIN logs AS t_count3 ON t_count3.type LIKE 'type3' AND t_count3.user_id=users.user_id
LEFT JOIN events AS t_count4 ON t_count4.user_id = users.user_id
WHERE computers.account_id=1 AND computers.computer_id in (1,2)
GROUP BY users.user_id
ORDER BY users.user_id ASC,computers.computer_id ASC;
If you choose to keep your current query structure for any reason, adapting it like so should make it work for you:
select *,ifnull(count1,0)+ifnull(count2,0)+ifnull(count3,0)+ifnull(count4,0) AS totalcount from
( select account_id, computer_id, computer_name
from computers
order by computer_id asc limit 0, 2
) as c
left join users
on users.computer_id = c.computer_id
left join
(select user_id, count(user_id) as count1
from logs
where logs.type like 'type1'
group by user_id) as t_count1
on t_count1.user_id = users.user_id
left join
(select user_id, ifnull(count(user_id),0) as count2
from logs
where logs.type like 'type2'
group by user_id) as t_count2
on t_count2.user_id = users.user_id
left join
(select user_id, count(user_id) as count3
from logs
where logs.type like 'type3'
group by user_id) as t_count3
on t_count3.user_id = users.user_id
left join
(select user_id, count(user_id) as count4
from events
group by user_id) as t_count4
on t_count4.user_id = users.user_id
where c.account_id = 1;
My advice would be to follow along each query to understand what you are asking SQL to do. To actually add all values together, you should be counting the number of records that are returned. Counting values of your primary keys helps you to count records. Also, using your other example, ifnull in the second example make sure that null values are not going to interfere with adding. "If a value is null make it 0 instead."
I currently have:
SELECT tbl_review.*, users.first_name, users.last_name, (
SELECT order_ns.tran_date
FROM order_ns
LEFT JOIN product_2_order_ns.external_order_id = order_ns.order_id
WHERE product_2_order_ns.bkfno IN :id
ORDER BY order_ns.trandate ASC
LIMIT 1
) as purchase_date
FROM tbl_review
LEFT JOIN users ON users.sequal_user_id = tbl_review.user_id
WHERE tbl_review.product_id IN :id AND tbl_review.approved = 1
Which, in its sub query, selects an order the user has which has a product in question (defined in :id) get the the oldest transaction date on file for one of the found orders.
I would really like to keep this to one call of the database (don't really want to call again for each returned user for just one field, or even do a range query of all users) but obviously this particular query isn't working.
What can I do, if anything, to get this working?
I cannot make the sub query into a join since they are two distinct pieces of data, the sub query needs to return detail for each row in the main query.
I think you just want a correlated subquery. It is unclear exactly what the relationship is between the inner query and the outer one. My guess is that it is on users and orders:
SELECT tbl_review.*, users.first_name, users.last_name,
(SELECT order_ns.tran_date
FROM order_ns LEFT JOIN
product_2_order_ns
on product_2_order_ns.external_order_id = order_ns.order_id and
product_2_order_ns.bkfno = tbl_review.product_id and
WHERE order_ns.user_id = tbl_review.user_id
ORDER BY order_ns.trandate ASC
LIMIT 1
) as purchase_date
FROM tbl_review LEFT JOIN
users
ON users.sequal_user_id = tbl_review.user_id
WHERE tbl_review.product_id IN :id AND tbl_review.approved = 1;
EDIT:
Oh, the inner query has no relationship to the outer query. Then it is easier. Move it to the from clause using cross join:
SELECT tbl_review.*, users.first_name, users.last_name,
innerquery.tran_date as purchase_date
FROM tbl_review LEFT JOIN
users
ON users.sequal_user_id = tbl_review.user_id cross join
(SELECT order_ns.tran_date
FROM order_ns LEFT JOIN
product_2_order_ns
on product_2_order_ns.external_order_id = order_ns.order_id
WHERE product_2_order_ns.bkfno IN :id
ORDER BY order_ns.trandate ASC
LIMIT 1
) innerquery
WHERE tbl_review.product_id IN :id AND tbl_review.approved = 1;
#Gordons answer is really close but I wanted it to return even if no data was found for tran_date so I changed my query to:
SELECT tbl_review.*, users.first_name, users.last_name, order_ns.tran_date
FROM tbl_review
LEFT JOIN users ON users.sequal_user_id = tbl_review.user_id
LEFT JOIN order_ns ON order_ns.order_id = (
SELECT order_ns.order_id
FROM order_ns
LEFT JOIN product_2_order_ns on product_2_order_ns.external_order_id = order_ns.order_id
WHERE product_2_order_ns.bkfno IN :id
ORDER BY order_ns.tran_date ASC
LIMIT 1
)
WHERE tbl_review.product_id IN :id AND tbl_review.approved = 1;
This will return the distinct data of tran_date irrespective of whether it is found or not.
With a Left Join i have this result.
Here the screen
http://f.cl.ly/items/373Y141r1K131d0n3f1q/Schermata%202013-04-01%20alle%2016.51.18.png
i want to show only record once time, without repeat it, but with a left join all my records are different.
what i have to do for show once all my records?
the query.
SELECT * FROM login_users
LEFT JOIN login_users_seguaci
ON login_users.user_id = login_users_seguaci.following
WHERE name LIKE ""
AND user_id != '1'
ORDER BY data DESC
SELECT x.*, y.*
FROM login_users x
LEFT JOIN
(
SELECT a.*
FROM login_users_seguaci a
INNER JOIN
(
SELECT following, MAX(DATA) max_data
FROM login_users_seguaci
GROUP BY following
) b ON a.following = b.following AND
a.DATA = b.max_date
) y ON x.user_id = y.following
// WHERE ... your condition here ...
ORDER BY t.data DESC