I am trying to figure out a complex (at least for me!) mysql query and hoped someone here might have some clue's for me..
I have 2 tables "Users" and "files".
Users:
id, name, address, etc..
Files:
id, user_id, file_name, etc..
I want to select all rows from Users and in the result create a last column that has a count of all file with where User.id = Files.user_id.
I tried SELECT * from Users UNION(SELECT COUNT Files.user_id WHERE Users.id = Files.user_id) but doesn't work of course..
select u.*, count(f.id)
from users u
left join files f on u.id = f.user_id
group by u.id
Related
There are three tables, I would like to get the count of a user's total tweets and the count of likes his total tweets received.
I tried to combine two queries to get what I want but failed. Have looked through several previous questions but still can't figure it out.
Users table
id
name
1
User1
Tweets table
id
UserId (foreign key)
content
1
User1
hello
Likes table
id
UserId (foreign key)
TweetId (foreign key)
1
User1
hello
First query:
SELECT Users.name, Users.id, COUNT(Tweets.UserId) AS UserTweetCount FROM Users
LEFT JOIN Tweets
ON Users.id = Tweets.UserId
GROUP BY Users.id
ORDER BY UserTweetCount DESC;
Second query:
SELECT Users.name, Users.id, COUNT(Likes.UserId) AS UserTweetBeLikedCount FROM Users
LEFT JOIN Likes
ON Users.id = Likes.UserId
GROUP BY Users.id;
I tried like below but would get wrong UserTweetBeLikedCount counts. The counts would be UserTweetCount's, not UserTweetBeLikedCount's. When I ran two queries separately, it worked well. But when I combined them together, it didn't work right.
Don't know how to display the right counts. Can someone give me hints to solve this, please?
SELECT Users.name, Users.id,
COUNT(Tweets.UserId) AS UserTweetCount, COUNT(Likes.UserId) AS UserTweetBeLikedCount
FROM Users
LEFT JOIN Tweets
ON Users.id = Tweets.UserId
LEFT JOIN Likes
ON Users.id = Likes.UserId
GROUP BY Users.id
ORDER BY UserTweetCount DESC;
I recommend using correlated subqueries for this:
SELECT u.*,
(SELECT COUNT(*)
FROM Tweets t
WHERE u.id = t.UserId
) AS UserTweetCount,
(SELECT COUNT(*)
FROM Likes l
WHERE u.id = l.UserId
) AS UserLikeCount
FROM Users u
ORDER BY UserTweetCount DESC;
As a note: For performance, you want indexes on Tweets(UserId) and Likes(UserId).
I have three tables:
table: users / columns: user_id, email, username
table: activities / columns: object, type, like_count
table: activities2 / columns: object, target_type, subject, type
The like_count in activities table has no problem and I count all of that with this query:
SELECT SUM(activities.like_count) AS likes, users.user_id, users.email, users.username
FROM activities
INNER JOIN users
ON activities.subject = users.user_id
GROUP BY user_id
But there is another count in activities table which is being inserted(NOT UPDATED) each time some other types of posts liked and I counted them by this query:
SELECT activities.subject, activities.object, COUNT(activities.type) AS likes
FROM activities
INNER JOIN activities2
ON activities.object = activities2.object AND activities2.target_type = 'parent'
WHERE activities2.type LIKE 'like_%'
GROUP BY activities2.subject
BUT the problem starts from here when I want to join them together! I want to count like_count + count of likes that inserted in that table(activities2) that contains string of 'like_' and beside this I want to join the subject(in activities table) which is related to user_id in the other table(users).
My last query is this:
SELECT users.user_id, users.email, users.username, activities.object, COUNT(activities.type)+SUM(activities.like_count) AS likes
FROM activities
INNER JOIN activities2
ON activities.object = activities2.object AND activities2.target_type = 'parent'
INNER JOIN users
ON activities.subject = users.user_id
WHERE activities2.type LIKE 'like_%'
GROUP BY users.user_id
The problem is when joining, it fetches the user information not for the one that I want.
In conclusion I want something like this:
user_id------email-----------------username----------object-------likes
2521---------a#b.com---------------abc---------------9578---------3
5484---------c#d.com---------------def---------------8547---------16
8431---------e#f.com---------------ghi---------------4584---------1
And offcourse the result is this but only likes are correct however columns of user_id, email, username that are in users table NOT!
I was wondering if you would help to fix it. I'm really tired of trying and facing to no result :(
users table data:
user_id-------------email---------------username
1-------------------a#b.com-------------abc
2-------------------c#d.com-------------def
3-------------------e#f.com-------------ghi
activities table data:
object----------type----------------like_count------subject
20--------------like_video----------0---------------1
20--------------like_photo----------0---------------2
33--------------like_music----------0---------------3
33--------------some_other_type-----5---------------6
33--------------some_other_type-----8---------------10
activities2 table data:
object------target_type-----subject-----type
20----------parent----------30----------like_video
21----------owner-----------40----------like_audio
22----------parent----------50----------something_not_start_with_like_
I want:
user_id------email-----------------username----------object-------likes
1------------a#b.com---------------abc---------------9578---------(sum of like_count + count of type which has like_ in first characters)
2------------c#d.com---------------def---------------8547---------(sum of like_count + count of type which has like_ in first characters)
3------------e#f.com---------------ghi---------------4584---------(sum of like_count + count of type which has like_ in first characters)
Consider joining the aggregate queries using derived tables and then run your addition calculation in the outer query. Also, below object column is removed from the second aggregate query's GROUP BY clause but still used in JOIN since you need summation at the subject level.
SELECT u.user_id, u.email, u.username, a.`object`, u.likes + a.likes as `total_likes`
FROM
(SELECT SUM(activities.like_count) AS likes, users.user_id, users.email, users.username
FROM activities
INNER JOIN users
ON activities.subject = users.user_id
GROUP BY user_id, users.email, users.username) u
INNER JOIN
(SELECT activities.subject, COUNT(activities.type) AS likes
FROM activities
INNER JOIN activities2
ON activities.object = activities2.object AND activities2.target_type = 'parent'
WHERE activities2.type LIKE 'like_%'
GROUP BY activities2.subject) As a
ON u.user_id = a.subject
I want to get information from two tables users and results.
users table has
id, name, email, password columns etc.
and results table has
id, user_id, last_attempt_time etc.
The result table gets populated every time a user takes a quiz.
I want to display user_id,name and last_attempt_time but my query returns oldest time and i have no idea how to solve this problem.
SELECT u.id,u.email,u.name,u.joined,r.last_attempt_time FROM users u
LEFT JOIN results r
ON u.id=r.user_id
GROUP BY u.id
ORDER BY u.id ASC
Try:
SELECT u.id,u.email,u.name,u.joined,MAX(r.last_attempt_time) AS LastAttempt
FROM users u left join results r on u.id=r.quiz_id
GROUP BY u.id,u.email,u.name,u.joined
ORDER BY u.id ASC
I'm trying to join multiple table to get single row result for each id. This result will be send to angular UI
I have 3 tables user, friends and trip
A user can have multiple friends but one trip
I like to get all details corresponding to a user in one row, probably friends as field like an array?
This is how my table looks.
http://sqlfiddle.com/#!9/0879d/2
https://gist.github.com/tomalex0/9dee4fff85583732e7d0
group_concat should do the trick for you:
SELECT u.*, t.*, friendlist
FROM user u
LEFT JOIN trip t ON u.id = t.user_id
LEFT JOIN (SELECT user_id, GROUP_CONCAT(CONCAT (name, '- ', email)) friendlist
FROM friends
GROUP BY user_id) f ON f.user_id = u.id
I just learned you can stack SQL queries instead of running 4 different ones and combining the data. So I'm read tutorials and stuff but still can't figure this certain one out.
SELECT ID,
(SELECT firstname
FROM user
WHERE ID = fundraiser.user_ID) AS firstname,
(SELECT lastname
FROM user
WHERE ID = fundraiser.user_ID) AS lastname,
(SELECT org_fund_id
FROM fundraiser
WHERE ID = fundraiser.ID) AS org_fund_ID,
(SELECT ref_ID
FROM fundraiser
WHERE ID = fundraiser.ID) AS ref_ID
FROM fundraiser
WHERE 1
ORDER BY org_fund_ID ASC
Here's the basic setup for the database/tables being called:
[fundraiser] - (ID, ref_ID, user_ID, org_fund_ID) and
[user] - (firstname, lastname)
Basically, I want to pull all of the fields from "fundraiser" from the database but get the corresponding "user.firstname" and "user.lastname" where "fundraiser.user_ID" = "user.ID".
So it would come out something like this as a row:
fundraiser.ID, fundraiser.user_ID, fundraiser.ref_ID, user.firstname, user.lastname
I've tried like 30 different ways of writing this query and all have failed. The error I get is "#1242 - Subquery returns more than 1 row".
Not sure how I can give you more information so you can visualize what I'm talking about, but I will provide whatever data I can.
Thanks in advance.
to select ALL columns:
SELECT *
FROM fundraiser f
INNER JOIN user u
ON u.ID = f.user_ID
ORDER BY f.ord_fund_id ASC;
to select needed columns:
SELECT
u.firstname,
u.lastname,
f.org_fund_id,
f.ref_ID
FROM fundraiser f
INNER JOIN user u ON u.ID = f.user_ID
ORDER BY f.ord_fund_id ASC;
this should be, what you need. See this Wikipedia page.