I am running a MySQL query to get all "users" with current orders.
(It is possible for a user to have more than 1 associated orders in the db/query).
However i also want to get the total order value for each user and total order count for each user that is being returned (within the below query).
I could do these calculations in PHP, but feel it is possible and would be neater all done within the same SQL query (if possible).
This is the basic query with no attempt to make the above calculations
SELECT u.UserID, u.UserName,
o.OrdersID, o.OrderProductName, o.OrderProductQT, o.OrderTotalPrice, o.tUsers_UserID, o.tOrderStatus_StatusID, o.OrderDate, o.OrderDateModified, o.OrderVoid, o.tProducts_ProductID,
os.OrderStatusName,
ud.UserDetailsName, ud.UserDetailsPostCode,
p.ProductName, p.ProductImage1
FROM tusers u
INNER JOIN torders o ON o.tUsers_UserID = u.UserID
INNER JOIN torderstatus os ON os.OrderStatus_StatusID = o.tOrderStatus_StatusID
INNER JOIN tuserdetails ud ON ud.tUsers_UserID = u.UserID
LEFT JOIN tproducts p ON p.ProductID = o.tProducts_ProductID
WHERE o.tOrderStatus_StatusID = ?
GROUP BY u.UserID
ORDER BY OrdersID DESC
I have tried various nested select queries, but none of them work (right)
Is what i want to do possible in SQL or should i just do it all in PHP once i have the returned query results?
Any advice is much appreciated
You can embed the slightly modified queries into another query. For instance:
SELECT userid, SUM(orderid) FROM orders GROUP BY userid
and
SELECT userid, SUM(distinct productid)
FROM
orders o
INNER JOIN orderlines ol on ol.orderid = o.orderid
GROUP BY
userid
can be combined to:
SELECT
u.userid
u.fullname,
(SELECT SUM(orderid)
FROM orders o
WHERE o.userid = u.userid) as ORDERCOUNT,
(SELECT SUM(distinct productid)
FROM
orders o
INNER JOIN orderlines ol on ol.orderid = o.orderid
WHERE
o.userid = u.userid) as UNIQUEPRODUCTS
FROM
users u
Note that the latter query will return all users and will return NULL for ORDERCOUNT or UNIQUEPRODUCTS when the subquery doesn't return anything (when a user doesn't have orders). Also, the query will fail when a subquery returns more than 1 row, which should never happen in the example I posted.
Related
I have a big data problem with MySQL.
I have:
a users table with 59033 rows, and
a user_notes table with 8753 rows.
But when I search which users have user note in some dates.
My query like this :
SELECT u.*, rep.name as rep_name FROM users as u
LEFT JOIN users as rep on rep.id = u.add_user
LEFT JOIN authorization on authorization.id = u.authorization
LEFT JOIN user_situation_list on user_situation_list.user_situation_id = u.user_situation
WHERE
EXISTS(
select * from user_notes
where user_notes.note_user_id = u.id AND user_notes.create_date
BETWEEN "2017-10-20" AND "2017-10-22"
)
ORDER BY u.lp_modify_date DESC, u.id DESC
Turn it around -- find the ids first; deal with the joins later.
SELECT u.*,
( SELECT rep.name
FROM users AS rep
WHERE rep.id = u.add_user ) AS rep_name
FROM (
SELECT DISTINCT note_user_id
FROM user_notes
WHERE create_date >= "2017-10-20"
AND create_date < "2017-10-20" + INTERVAL 3 DAY
) AS un
JOIN users AS u ON u.id = un.note_user_id
ORDER BY lp_modify_date DESC, id DESC
Notes
No GROUP BY needed;
2 tables seem to be unused; I removed them;
I changed the date range;
User notes needs INDEX(create_date, note_user_id);
Notice how I turned a LEFT JOIN into a subquery in the SELECT list.
If there can be multiple rep_names, then the original query is "wrong" in that the GROUP BY will pick a random name. My Answer can be 'fixed' by changing rep.name to one of these:
MAX(rep.name) -- deliver only one; arbitrarily the max
GROUP_CONCAT(rep.name) -- deliver a commalist of names
Rewriting your query to use a JOIN rather than an EXISTS check in the where should speed it up. If you then group the results by the user.id it should give you the same result:
SELECT u.*, rep.name as rep_name FROM users as u
LEFT JOIN users as rep on rep.id = u.add_user
LEFT JOIN authorization on authorization.id = u.authorization
LEFT JOIN user_situation_list on user_situation_list.user_situation_id = u.user_situation
JOIN user_notes AS un
ON un.note_user_id
AND un.create_date BETWEEN "2017-10-20" AND "2017-10-22"
GROUP BY u.id
ORDER BY u.lp_modify_date DESC, u.id DESC
I have a projects table and a tasks table I want to do a query that gets all projects and the sum of the time_spent columns grouped by project id. So essentially list all projects and get the total of all the time_spent columns in the tasks table belonging to that project.
With the query posted below I get the latest added time_spent column and not the sum of all the columns.. :S
Below is the query I have at the moment:
SELECT `projects`.`id`, `projects`.`description`, `projects`.`created`,
`users`.`title`, `users`.`firstname`, `users`.`lastname`, `users2`.`title`
as assignee_title, `users2`.`firstname` as assignee_firstname,
`users2`.`lastname` as assignee_lastname,
(select sum(tasks2.time_spent)
from tasks tasks2
where tasks2.id = tasks.id)
as project_duration
FROM (`projects`)
LEFT JOIN `users`
ON `users`.`id` = `projects`.`user_id`
LEFT JOIN `users` as users2
ON `users2`.`id` = `projects`.`assignee_id`
LEFT JOIN `tasks` ON `tasks`.`project_id` = `projects`.`id`
GROUP BY `projects`.`id`
ORDER BY `projects`.`created` DESC
Below is my projects table:
Below is my tasks table:
Thanks in advance!
Usually this query will help you.
SELECT p.*, (SELECT SUM(t.time_spent) FROM tasks as t WHERE t.project_id = p.id) as project_fulltime FROM projects as p
In your question, you don't say about users. Do you need users?
You are on right way, maybe your JOINs can't fetch all data.
This query should do it for you.
Note, whenever you do a group by you must include every column that you select from or order by. Some MySql installations don't prevent you from doing this, but in the end it results in an incorrect result set.
As well you should never do a query as part of your SELECT statement, known as a sub-query, as it will result in an equal amount of additional queries in relation to the number of rows returned. So if you got 1,000 rows back, it would result in 1,001 queries instead of 1 query.
SELECT
p.id,
p.description,
p.created,
u.title,
u.firstname,
u.lastname,
a.title assignee_title,
a.firstname assignee_firstname,
a.lastname assignee_lastname,
SUM(t.time_spent) project_duration
FROM
projects p
LEFT JOIN
users u ON
u.id = p.user_id
LEFT JOIN
users a ON
a.id = u.assignee_id
LEFT JOIN
tasks t ON
t.project_id = p.id
GROUP BY
p.id,
p.description,
p.created,
u.title,
u.firstname,
u.lastname,
a.title,
a.firstname,
a.lastname
ORDER BY
p.created DESC
I have a problem trying to JOIN an empty table (comments table) to my existing prepared statement.
This is working perfectly:
// prepare images
if ($stmt = $mysqli->prepare(" SELECT uu.*, m.*,
(
SELECT COUNT(*)
FROM img_likes AS t
WHERE t.img_id = uu.imgID AND t.user_id = ?
) AS user_likes,
(
SELECT COUNT(*)
FROM img_likes AS t
WHERE t.img_id = uu.imgID
) AS total_likes
FROM user_uploads AS uu
INNER JOIN members AS m ON m.id = uu.user_id
ORDER BY up_time DESC")) {
$stmt->bind_param('i', $user_id);
$stmt->execute(); // get imgs
// foreach print images
// working as expected
}
And I don't know why if I JOIN another table (img_comments) that is empty, the images are not printed... if I add a row to the table and refresh the page, one image is printed...
The statement that I'm trying and it's not working is this:
SELECT uu.*, m.*, ic.*,
(
SELECT COUNT(*)
FROM img_likes AS t
WHERE t.img_id = uu.imgID AND t.user_id = ?
) AS user_likes,
(
SELECT COUNT(*)
FROM img_likes AS t
WHERE t.img_id = uu.imgID
) AS total_likes
FROM user_uploads AS uu
INNER JOIN members AS m ON m.id = uu.user_id
INNER JOIN img_comments AS ic ON ic.img_id = uu.imgID
ORDER BY up_time DESC
Why is only printing images based on the number of the table rows?? I also tried LEFT JOIN but I'm not too familiareize with this. I only use INNER JOIN in other scripts and I never had a problem like this.
I would appreciate any optimization to my query.
What does an inner join do? It joins all records of table a with all matching records of table b. So when there are no records in table b, there is no match for any record of table a, hence no result at all. Why does this surprise you?
A left join is an outer join (short for LEFT OUTER JOIN). It means: Give me all records of table a with all matching records of table b, and when there is no match then give me the record of table a anyhow. This seems to be what you are wanting here. But you say you tried it. I don't see how this would fail in your query.
A typical error for an outer join not to work would be to have some field of b in your where clause (e.g. where b.id > 100). As the outer-joined records have no matching b record, all b fields are null, so that such a where clause would fail. You'd just get matches again, just like with the inner join.
EDIT: As to optimization, you can get the two counts in one pass by counting conditionally:
SELECT
uu.*, m.*, ic.*,
il.count_user AS user_likes,
il.count_total AS total_likes
FROM user_uploads AS uu
INNER JOIN members AS m ON m.id = uu.user_id
LEFT OUTER JOIN img_comments AS ic ON ic.img_id = uu.imgID
LEFT OUTER JOIN
(
select
img_id,
count(*) as count_total,
count(case when t.user_id = ? then 1 end) as count_user
from img_likes
group by img_id
) AS il ON il.img_id = uu.imgID
ORDER BY uu.up_time DESC;
As far as I know, INNER JOIN will only retrieve data which have both data. So if let say the table that you join have no data with that join condition. It will not return any data at all.
LEFT JOIN is just a normal join. It will retrieve data on both table. But if the joined table is empty, then only the primary table will have data, the secondary table will have null as its data.
You can just modify your code, replacing INNER JOIN with LEFT JOIN and see if it works/
I have a MYSQL query who have to list all post i want it to post. But it dont do it. It shows posts when i have more then one post in the table "meaOrder" with the same "ordCode". But when i have only on post in meaOrder, i don't show it. What can i do?
SELECT koden, wish, rnamn, bild, pris, cname, onsktext
FROM (
SELECT m.wishText as onsktext, m.meaOID as midn, m.ordcode as koden, w.wish as wish, r.meaName as rnamn, r.meaImg as bild,
r.meaPrice as pris, k.catName as cname from cats k, meals r, wishes w,
meaOrder m
join orders c on c.ordNR=4401
WHERE c.ordStatus=1 AND m.ordNR=c.ordNR AND m.meaID=r.meaID AND m.wishesID=w.id
AND r.catID=k.catID
) T
GROUP BY koden, rnamn, bild, pris, cname
ORDER BY midn DESC
TABLE orders
http://grab.by/m74E
TABLE meaOrder http://grab.by/m74Q
Try replacing the JOIN with RIGHT JOIN in this case. The difference is explained at JOIN Syntax page in MySQL docs . In short - JOIN returns row only if there are corresponding rows in both joined tables (inner join). LEFT JOIN / RIGHT JOIN return all rows from one of the tables and corresponding row if it exists from the other table (those are outer joins)
Do you need a subselect?
This seems to cover it:-
SELECT m.ordcode AS koden, w.wish AS wish, r.meaName AS rnamn, r.meaImg AS bild, r.meaPrice AS pris, k.catName AS cname, m.wishText AS onsktext
FROM cats k
INNER JOIN meals r ON r.catID = k.catID
INNER JOIN meaOrder m ON m.meaID = r.meaID
INNER JOIN wishes w ON m.wishesID = w.id
INNER JOIN orders c ON m.ordNR = c.ordNR
WHERE c.ordStatus = 1
AND c.ordNR = 4401
GROUP BY m.ordcode, r.meaName, r.meaImg, r.meaPrice, k.catName
ORDER BY midn DESC
I've got reporting of a user's score everytime it happens. Now I want to show the best score a user has had. The table set up is like this:
Player(id, name)
PlayerHasAchievement(id, playerId,
achievementId)
Achievement(id, type, amount, time)
This is what I have right now:
$query = "SELECT MAX(ach.amount) as amount, p.username, ach.time
FROM achievement as ach
INNER JOIN playerHasAchievement as playAch ON ach.id = playAch.id
INNER JOIN player as p ON p.userId = playAch.userid
WHERE ach.type = 2
GROUP BY amount
ORDER by `amount` DESC
LIMIT $amount";
I tried to select it distinctly but it didn't work. I'm stumped, it's supposed to be so easy! Thanks for reading, I'll be grateful for any help!
The problem is the the ach.time you are getting is not the same row as the MAX(amount). Join another subquery to get the MAX(amount) first.
Note: In the table definitions you posted, playerHasAchievement has a field playerId not userId
SELECT MAX(ach.amount) as amount, p.username, MAX(ach.time) MaxTime
FROM achievement as ach
INNER JOIN playerHasAchievement as playAch ON ach.id = playAch.id
INNER JOIN player as p ON p.userId = playAch.playerId
INNER JOIN (
SELECT playAch.playerId, MAX(ach.amount) as MaxAmount
FROM achievement as ach
INNER JOIN playerHasAchievement as playAch ON ach.id = playAch.id
WHERE ach.type = 2
GROUP BY playAch.playerId
) g ON p.playerId = g.playerId AND ach.amount = g.MaxAmount
WHERE ach.type = 2
GROUP BY p.playerId
ORDER by `amount` DESC
LIMIT $amount";
The reason why we group the outer query, is to avoid ties - say a player had the same score twice.
In your join on line 3 don't you really want
INNER JOIN playerHasAchievement as playAch ON ach.id = playAch.achievementId
and others are correct, you need to group by your non aggregate columns, not the aggregate one.
Assuming your db layout is as specified in the question here is the query I would use.
SELECT ach.amount, p.Name, ach.time
FROM achievement as ach
JOIN playerHasAchievement as playAch ON ach.id=playAch.achievementId
JOIN player AS p ON p.id = playAch.playerId
WHERE ach.type = 2
AND ach.amount = (SELECT MAX(ach.amount)
FROM achievement as ach
JOIN playerHasAchievement as playAch ON ach.id=playAch.achievementId
JOIN player AS p ON p.id = playAch.playerId
WHERE ach.type = 2)
GROUP BY ach.amount
ORDER by ach.time
taking the first result (in case there are multiples of the same score) will give you the high score and the lowest time.
Hope that helps!
You are not using group by appropriately, as you are only grouping by amount.
What about the user name and the time?