I have 3 tables:
Users
| id | name |
|----|-------|
| 1 | One |
| 2 | Two |
| 3 | Three |
Likes
| id | user_id | like |
|----|---------|-------|
| 1 | 1 | 3 |
| 2 | 1 | 5 |
| 3 | 2 | 1 |
| 4 | 3 | 2 |
Transations
| id | user_id | transaction |
|----|---------|-------------|
| 1 | 1 | -1 |
| 2 | 2 | 5 |
| 3 | 2 | -1 |
| 4 | 3 | 10 |
I need get sum of likes.like and transations.transation for each user and then sort it by its result.
I was able to do it for users and likes:
select users.*, sum(likes.like) as points
from `users`
inner join `likes` on `likes`.`user_id` = `users`.`id`
group by `users`.`id`
order by points desc
But then I add transactions table like this:
select users.*, (sum(likes.like)+sum(transactions.`transaction`)) as points
from `users`
inner join `likes` on `likes`.`user_id` = `users`.`id`
inner join `transactions` on `transactions`.`user_id` = `users`.`id`
group by `users`.`id`
order by points desc
It is show wrong results.
I expecting to see:
| id | name | points |
|----|-------|--------|
| 3 | Three | 12 |
| 1 | One | 7 |
| 2 | Two | 5 |
But get this instead:
| id | name | points |
|----|-------|--------|
| 3 | Three | 12 |
| 1 | One | 6 |
| 2 | Two | 5 |
So, how sort users by sum likes.like and transations.transation?
Thank you!
Since there's not a 1-to-1 relationships between transactions and likes, I think you need to use subqueries:
select users.*,
(select sum(points) from likes where user_id = users.id) as points,
(select sum(transaction) from transactions where user_id = users.id) as transactions
from users
order by points desc
Updated after more explanation of requirements:
select users.*,
(select sum(points) from likes where user_id = users.id) +
(select sum(transaction) from transactions where user_id = users.id) as points
from users
order by points desc
Related
Attempting to join two tables on user_id. The users table has unique id for each user. The user_codes table can have multiple rows with the same user_id. I only want to return 1 row from the joined user_codes table, where code_count is the largest.
users Table
| id | email |
| -------- | --------------- |
| 1 | user1#gmail.com |
| 2 | user2#gmail.com |
| 3 | user3#gmail.com |
user_code TABLE
| user_id | invite_code | count |
| -------- | ----------- | ------|
| 1 | X49MCL1 | 40 |
| 1 | K59CLT9 | 1000 |
| 2 | X5BC924 | 15 |
| 2 | 38DF80L | 8 |
| 3 | 641020T | 22 |
EXPECTED RESULT
| id | email | invite_code | count |
| --- | --------------- | ----------- | ------|
| 1 | user1#gmail.com | K59CLT9 | 1000 |
| 2 | user2#gmail.com | X5BC924 | 15 |
| 3 | user3#gmail.com | 641020T | 22 |
The query result only includes a single instance of each user found in the user_codes table with the highest count.
Here is the closest query I could get, but it only returns the invite_code and count for the first user.
SELECT a.id, a.email, b.invite_code, b.count
FROM users a
LEFT JOIN user_codes b
ON b.user_id = a.id
AND b.count = (SELECT MAX(count) FROM user_codes GROUP BY b.user_id)
The above query returns the result:
| id | email | invite_code | count |
| --- | --------------- | ----------- | ------ |
| 1 | user1#gmail.com | K59CLT9 | 1000 |
| 2 | user2#gmail.com | `NULL` | `NULL` |
| 3 | user3#gmail.com | `NULL` | `NULL` |
I can't seem to figure out how/why the records after the first one don't include the invite_code and the count.
Thanks for help!
On MySQL 8+, I suggest using the RANK() window function:
WITH cte AS (
SELECT u.id, u.email, uc.invite_code, uc.count,
RANK() OVER (PARTITION BY u.id ORDER BY uc.count DESC) rnk
FROM users u
INNER JOIN user_code uc
ON uc.user_id = u.id
)
SELECT id, email, invite_code, count
FROM cte
WHERE rnk = 1;
The RANK() function will also match multiple records per user tied for the highest count.
You might be able to salvage your current attempt by correlating the user inside the subquery to the outer query:
SELECT a.id, a.email, b.invite_code, b.count
FROM users a
LEFT JOIN user_codes b
ON b.user_id = a.id AND
b.count = (SELECT MAX(uc.count) FROM user_codes uc WHERE uc.user_id = a.id);
My Structure
I have three (hypothetical) tables; Users, movies, sessions.
> SELECT * FROM users
+----+---------------------------+
| id | email |
+----+---------------------------+
| 5 | abcdefghijklmno#gmail.com |
+----+---------------------------+
> SELECT * FROM movies
+----+---------+---------+--------------+
| id | title | user_id | total_watches|
+----+---------+---------+--------------+
| 1 | X-men | 1 | 1 |
| 2 | Blade | 1 | 1 |
| 3 | Goonies | 1 | 1 |
+----+---------+---------+--------------+
> SELECT * FROM sessions
+----+---------+---------+------------+
| id | user_id | show_id | total_time |
+----+---------+---------+------------+
| 1 | 1 | 1 | 5 |
| 2 | 1 | 1 | 30 |
| 3 | 1 | 1 | 5 |
+----+---------+---------+------------+
What I want
I want to get an overview of a user's movie activity in one query, so would like to retrieve the data in the following format:
+----+---------------------------+---------------+----------------+
| id | email | total_time | total_watches |
+----+---------------------------+---------------+----------------+
| 5 | abcdefghijklmno#gmail.com | 40 | 3 |
+----+---------------------------+---------------+----------------+
What I've tried
SELECT users.id, users.email, SUM(movies.total_watches) AS total_watches, SUM(sessions.total_time) AS total_time
FROM users
JOIN movies ON users.id = movies.user_id
JOIN sessions ON users.id = sessions.user_id
GROUP BY users.id
This returns (minus a couple of columns):
+------------------+---------------+---------------+
| email | total_watches | total_time |
+------------------+---------------+---------------+
| abcdef#gmail.com | 9 | 120 |
+------------------+---------------+---------------+
Summary
I understand that the extra session join creates three rows for every movie and therefore trebles the SUM results, so how do I get the 'flattened' data? I have tried other group by combinations with no luck.
As suggested in comments above, your current table structure requires further normalization.
Now, for this table structure, one hacky way is to divide the SUM by Count of rows from the other table (causing duplication due to JOIN), to counter the effect of duplication.
So, the SUM of total_watches can be divided by the Count of rows from the sessions table for a user id. Similarly, the SUM of total_time can be divided by the Count of rows from the movies tables.
SELECT users.id,
SUM(movies.total_watches)/COUNT(DISTINCT sessions.id) AS total_watches,
SUM(sessions.total_time)/COUNT(DISTINCT movies.id) AS total_time
FROM users
JOIN movies ON users.id = movies.user_id
JOIN sessions ON users.id = sessions.user_id
GROUP BY users.id
Result
| id | total_watches | total_time |
| --- | ------------- | ---------- |
| 1 | 3 | 40 |
View on DB Fiddle
I have two tables, users and survey. I want query the table user and to join the table survey in a way that only the survey record with the lowest value is returned for each record in user table.
I want to avoid subqueries and temporary tables.
table users:
--------------
| uid | name |
--------------
| 1 | mike |
| 2 | john |
| 3 | bill |
--------------
table survey:
----------------------
| id | uid | value |
----------------------
| 1 | 3 | 9 |
| 2 | 3 | 5 |
| 3 | 1 | 3 |
| 4 | 1 | 7 |
| 5 | 1 | 2 |
| 6 | 2 | 4 |
| 7 | 2 | 9 |
| 8 | 1 | 0 |
| 9 | 2 | 5 |
---------------------
expected output:
---------------------
| id | name | value |
---------------------
| 8 | mike | 0 |
| 2 | bill | 5 |
| 6 | john | 4 |
---------------------
What kind of JOIn should I do, or how should I write the query?
The following query gets all rows with minimum value (doesn't exist another survey with value under the selected value)
Try this:
SELECT u.*, s.value
FROM survey s
JOIN users u
ON s.uid = u.uid
WHERE NOT EXISTS(
SELECT 'maximum'
FROM survey s2
WHERE s2.uid = s.uid
AND s2.value < s.value)
You could use something like this:
select s.id, u.name, y.min_value
from
(
select uid, min(value) as min_value
from survey
group by uid
) y
join survey s
on s.value = y.min_value
and s.uid = y.uid
join user u
on u.uid = y.uid
I think this will help you
SELECT * FROM SURVEY S
INNER JOIN USERS U
ON S.UID=U.UID
QUALIFY ROW_NUMBER() OVER (PARTITION BY S.UID ORDER BY S.VALUE1 ASC )=1;
I am trying to create a query with a GROUP_CONCAT added as a new column in my current query, first here are my tables:
Users table
+----+----------+--------------+
| id | username | date_created |
+----+----------+--------------+
| 1 | user1 | 2000-03-16 |
| 2 | user2 | 2001-05-14 |
| 3 | user3 | 2002-01-13 |
| 4 | user4 | 2003-03-14 |
+----+----------+--------------+
Shifts table
+----+------------+--------------+
| id | shift_name | date_created |
+----+------------+--------------+
| 1 | shift1 | 2002-05-10 |
| 2 | shift2 | 2002-07-11 |
| 3 | shift3 | 2002-09-23 |
+----+------------+--------------+
Accounts table
+----+--------------+--------------+
| id | account_name | date_created |
+----+--------------+--------------+
| 1 | account1 | 2001-05-01 |
| 2 | account2 | 2001-05-02 |
| 3 | account3 | 2001-05-03 |
+----+--------------+--------------+
Shift Mapping table
+----+---------+----------+------------+
| id | user_id | shift_id | account_id |
+----+---------+----------+------------+
| 1 | 1 | 1 | 1 |
| 2 | 1 | 2 | 2 |
| 3 | 3 | 1 | 1 |
+----+---------+----------+------------+
basically, I want a query that gets all the user (to display in a table) with a custom column that shows all shift that is attach to that user(if there is no shift attach to that obviously has a null result)
Here is the query I've done so far:
SELECT users.id AS user_id, users.username, users.date_created,
GROUP_CONCAT(DISTINCT (t.shift_name)) AS shifts
FROM (`users`)
LEFT JOIN
(SELECT s.shift_name, sm.user_id FROM shift_map sm
LEFT JOIN shifts s ON sm.shift_id = s.id) t
ON users.id = t.user_id
GROUP BY user_id
ORDER BY `users`.`date_created` DESC;
Now there is no problem getting the users with a shift attach to it, my problem is that the users with no shifts attach to only returns 1 result which is caused by the GROUP BY user_id how can I exclude the users with no shift in the GROUP BY or how can I return all the users with attached shifts and with no attach shifts? Thanks.
Update
Here is the example result I want to see:
+---------+----------+--------------+----------------+
| user_id | username | date_created | shifts |
+---------+----------+--------------+----------------+
| 1 | user1 | 2000-03-16 | shift1,shift2 |
| 2 | user2 | 2001-05-14 | (NULL) |
| 3 | user3 | 2002-01-13 | shift1 |
| 4 | user4 | 2003-03-14 | (NULL) |
+---------+----------+--------------+----------------+
My problem in my query is that it only shows only 1 user with null shifts.
SELECT users.id AS user_id, users.username, users.date_created,
GROUP_CONCAT(DISTINCT (t.shift_name)) AS shifts
FROM (`users`)
LEFT JOIN
(SELECT s.shift_name, sm.user_id FROM mapping sm
LEFT JOIN shifts s ON sm.shift_id = s.id) t
ON users.id = t.user_id
GROUP BY username
ORDER BY user_id
+---------+----------+--------------+---------------+
| user_id | username | date_created | shifts |
+---------+----------+--------------+---------------+
| 1 | user1 | 2000-03-16 | shift1,shift2 |
| 2 | user2 | 2001-03-16 | NULL |
| 3 | user3 | 2002-03-16 | shift1 |
| 4 | user4 | 2003-03-16 | NULL |
+---------+----------+--------------+---------------+
My Bad, I can just use the simple LEFT JOIN:
SELECT users.id AS user_id, users.username, users.date_created,
GROUP_CONCAT(DISTINCT (shift.shift_name)) AS shifts
FROM (`users`)
LEFT JOIN shifts_map ON users.id = shifts_map.user_id
LEFT JOIN shifts ON shifts_map.shift_id = shift.id
GROUP BY user_id
ORDER BY `users`.`date_created` DESC;
I am just complicating the query, Forgot that the simple LEFT JOIN can do the trick. Thanks.
I'm stucked with a Mysql query, can you help me?
I have two tables:
user
id | name
1 | foo1
2 | foo2
3 | foo3
posts
id | id_user | created_at | kind
1 | 2 | 15-03-2011 | a
1 | 2 | 14-03-2011 | b
2 | 3 | 13-03-2011 | a
1 | 2 | 12-03-2011 | b
What I want is to retrieve the latest post of each user (the kind doesn't matter) ordered by de creation date.
How can I do that?
Thank you guys
One possible query is:
SELECT
u.id,
(SELECT MAX(p.created_at) FROM posts AS p WHERE u.id = p.id_user) AS latest
FROM
user AS u;
although the dependent subquery may not be the best solution to this. Example output:
users:
+------+------+
| id | name |
+------+------+
| 0 | test |
| 1 | one |
+------+------+
posts:
+------+---------+------------+------+
| id | id_user | created_at | kind |
+------+---------+------------+------+
| 0 | 0 | 2011-02-05 | a |
| 1 | 1 | 2011-02-06 | b |
| 2 | 0 | 2011-02-03 | a |
| 3 | 1 | 2011-02-02 | b |
+------+---------+------------+------+
output:
+------+------------+
| id | latest |
+------+------------+
| 0 | 2011-02-05 |
| 1 | 2011-02-06 |
+------+------------+
You can also add an ORDER BY latest DESC to the end of the query if you wish to get an ordered list of the latest posts across all user IDs.
Using a GROUP BY on id_user and the max post date ?
Something like that :
SELECT u.name, p.id_user, MAX( p.created_at )
FROM posts AS p
LEFT JOIN user AS u ON u.id
WHERE p.id_user = u.id
GROUP BY id_user